WO2014077462A1 - Apparatus for measuring eye rotation angle for setting length of corridor of progressive lens and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens, which are capable of measuring the length of a user custom-made corridor by measuring a reading habit (i.e., a behavior pattern) of a glasses-wearer in fabricating a progressive lens. The apparatus includes a near Pupil Distance (PD) apparatus for measuring an angle, height, and direction when the subject of measurement who wears glasses grasps a book and a sensing apparatus for measuring angles of a face and a gaze of the subject of measurement when the subject of measurement gazes steadily at the near PD apparatus and transferring measured result values to the near PD apparatus when the sensing apparatus is mounted on the frame of the glasses by a jig.

Description

APPARATUS FOR MEASURING EYE ROTATION ANGLE FOR SETTING LENGTH OF CORRIDOR OF PROGRESSIVE LENS AND METHOD THEREOF

The present invention relates to an apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens, and more particularly, to an apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens, which are capable of measuring the length of a user custom-made corridor by measuring a reading habit (i.e., a behavior pattern) of a glasses-wearer in fabricating a progressive lens.

The application claims the benefit of Korean Patent Application No. 10-2012-0128580, filed on November 14, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

In case of a normal eye, a far point of an eye is infinite and a near point of an eye is about 25 cm. However, an eye not having the above far point and an eye not having the above near point are called myopia and hyperopia, respectively.

Myopia refers to abnormal visual power when a minimum distance where an object can be clearly seen is short because an eye lens is more convex than that of a normal eye or a distance between the eye lens and the retina is long and thus the far point is shorter than infinity. Hyperopia refers to abnormal visual power because an eyeball is shorter than that of a normal eye or an eye lens is thinner than that of a normal eye due to a reduction in the elasticity of a ciliary body muscle and thus a near point is longer than 25 cm.

An glasses lens that is worn in order to correct an eye refraction state in which it is difficult to see both a near distance and a long distance due to a reduction of the power of accommodation of the near point and the far point includes a progressive addition lens (hereinafter referred to as a 'progressive lens').

In order to fabricate the above-described progressive lens, physical characteristics and eye habits unique to a person who wears glasses (hereinafter referred to as the 'subject of measurement'), such as a long distance or near distance gaze location or direction, a distance between two pupils, a facial structure, a reading habit, a rotation angle of a pupil, and a facial tilt, must be taken into consideration.

The above considerations are called so-called 'parameters for fabricating a glasses lens'. The parameters include, for example, an infinite distance binocular pupil distance, an infinite distance monocular pupil distance, a near distance binocular pupil distance, a near distance monocular pupil distance, a horizontal distance and a vertical distance (u/v) from the center point of the frame of glasses to the center of the pupil of an eye, a horizontal distance of the lens insertion unit of the frame of glasses (i.e., BOX A), a vertical distance of the lens insertion unit of the frame of glasses (i.e., BOX B), the longest distance from the center point of the frame of glasses to the lens insertion unit of the frame of glasses (i.e., BOX ED), a horizontal distance between the lens insertion units of the frame of glasses on the left and right sides (i.e., DBL), a vertical distance from the center of the pupil of an eye to the lens insertion units of the frame of glasses (i.e., an eye point), a face tilting angle of a front gaze state of the subject of measurement, an angle formed between a vertical line perpendicular to a lateral reference horizontal plane of the subject of measurement and a side line of the spectacle lens(i.e., a pantoscopic tilt), a distance from the vertex of the cornea of the subject of measurement to the optical center point of a glasses lens (i.e., a vertex cornea distance), an angle formed by a virtual line from the center of the frame of glasses to the longest distance on the left or right side of the glasses lens that is bent toward the face of the subject of measurement left or right when wearing the glasses and a virtual line horizontally extended from the center of the frame of glasses to the left or right side (i.e., a face form angle), and a face rotation angle of the front gaze state of the subject of measurement. The parameters must be precisely measured and applied to a glasses lens when fabricating a special glasses lens, such as a progressive lens or a progressive multifocal lens, as well as a common glasses lens.

In relation to the parameters, Korean Patent Laid-Open Publication No. 10-2004-0030594 discloses a glasses lens design method into which an eyeball movement (on the listing side) has been taken into consideration in order to easily fabricate a glasses lens having higher performance. The above patent discloses a glasses lens design method and a glasses lens in which a visual power evaluation function (i.e., log MAR) commonly derived from an actual visual power measurement value V is used as an evaluation function regarding visual power that forms an advantage function used in optimization calculation. In this case, assuming that a top curve is the aberration of a common glasses lens and the remaining astigmatism (i.e., a phenomenon in which an image of an object spaced apart from the main axis of the lens become obscure in a ring shape or a radial form) is defined by a glasses lens design into which the listing side has been taken into consideration, the visual power evaluation function (log MAR) is represented by Equation below (i.e., the visual power evaluation function (log MAR)= log₁₀ (1/V (a top curve, the remaining astigmatism))).

Furthermore, Korean Patent Laid-Open Publication No. 10-2009-0066296 discloses an apparatus and method for determining one or more factors of the directions of a glasses lens for correction for a person who will wear glasses in the state in which the person wears the glasses. This patent discloses an optical design method for a correction lens, including the steps of installing a location identification system in a frame or an exhibition lens installed in the frame, wherein the location identification system includes one or more identification devices having one or more known geometric characteristics; capturing an image of a vertical device in a vertical face plane in a two-dimensional manner; measuring the captured geometric characteristics of an image of the identification device that depends on the known geometric characteristics of the identification device by processing the captured image; and calculating one or more factors of the direction of the lens by comparing the captured geometric characteristic and the known geometric characteristic.

In the prior arts, however, a process of fabricating an apparatus for implementing a complicated equation or algorithm for measuring the parameters for fabricating a glasses lens is very complicated because the complicated equation or algorithm is used, and the size of a device needs to be increased.

Furthermore, since physical characteristics or eye habits unique to the subject of measurement are not taken into consideration, there is a need for a method of measuring parameters for fabricating a glasses lens and a measurement apparatus for implementing the method, which can be manipulated more precisely and easily by taking eye habit unique to the subject of measurement into consideration as compared with the prior arts, can be implemented in a small size and can be carried.

One or more embodiments of the present invention has been made in view of the above problems, and it is an aspect of the present invention to provide an apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens, which are capable of setting the length of the corridor of a user custom-made progressive lens by measuring an angle, distance, and height when a book is grasped, a head bow and an angle of a gaze when reading a book, and an eye rotation angle.

In an aspect of the present invention, an apparatus for measuring an eye rotation angle for setting a length of a corridor of a progressive lens includes a near Pupil Distance (PD) apparatus for measuring an angle, height, and direction when the subject of measurement who wears glasses grasps a book and a sensing apparatus for measuring angles of a face and a gaze of the subject of measurement when the subject of measurement gazes steadily at the near PD apparatus and transferring result values to the near PD apparatus when the sensing apparatus is mounted on a frame of the glasses by a jig.

The near PD apparatus may calculate an eye rotation angle according to the measured result values transferred from the sensing apparatus.

The near PD apparatus may include a screen module configured to have an input/output function, a camera module configured to photograph a surrounding environment in real time, a sensor module configured to sense behavior patterns of the subject of measurement, a Radio Frequency (RF) module configured to perform wireless communication with the sensing apparatus, and an operation module configured to store and/or process pieces of information received from the screen module, the camera module, the sensor module, and the RF module.

The sensing apparatus may include a sensor and RF module configured to measure a head bow angle and direction of the subject of measurement and send the result values to the near PD apparatus, an operation module configured to store and/or process information received from the RF module, and a power module configured to supply a power source itself or receive a power source from the near PD apparatus.

In another aspect of the present invention, a method of measuring an eye rotation angle for setting a Length of a Corridor (LOC) of a progressive lens includes measuring the eye rotation angle for setting the LOC in a state in which a sensing apparatus for measuring face and gaze angles of the subject of measurement have been mounted on glasses. Here, measuring the eye rotation angle may include measuring a head bow angle and direction of the subject of measurement by using a sensor module included in the sensing apparatus, measuring a head bow angle and direction of the subject of measurement by using a camera module built in a near PD apparatus for measuring behavior patterns of the subject of measurement and measuring an angle, direction, and height of the near PD apparatus when the subject of measurement reads a book by using a sensor module built in the near PD apparatus, measuring an eye rotation angle according to a reading habit of a person who wears the glasses by measuring a head bow angle of the person and an angle and posture when the person reads a book, and setting the LOC based on information on measured the eye rotation angle.

As can be clearly seen from the above description, the apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens according to an aspect of the present invention are advantageous in that the setting of the length of a corridor into which physical characteristics and eye habits unique to the subject of measurement have been into consideration can be performed precisely and conveniently on the basis of an image of the subject of measurement that is naturally captured.

Furthermore, there are advantages in that a precise product can be fabricated and a manufacturing time can be significantly reduced in fabricating functional glasses lenses having complicated manufacturing steps and requiring a precise test, such as progressive multifocal lenses, myopia control lenses, and eye fatigue reduction lenses.

In addition, cumbersome problems in which lots of glasses lenses have to be frequently replaced and lots of tests have to be performed can be significantly reduced, an optimized custom-made visual power correction product can be selected, and parameters for fabricating a variety of glasses lenses can be measured precisely and easily in association with a portable computer.

FIGS. 1 and 2 are an exemplary diagram and a block diagram showing the construction of an apparatus for measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention.

FIG. 3 is a block diagram showing a method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention.

FIGS. 4 and 5 are exemplary diagrams showing a process of measuring a Pantoscopic Tilt (PT) in the state in which glasses are worn and an eye height is fixed in the method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention.

FIGS. 6 and 7 are exemplary diagrams showing a change of a head bow angle and the length of a corridor when a PT is positive and negative, respectively, in the method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention.

Hereinafter, some exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings to such an extent that a person having ordinary skill in the art to which the present invention pertains can readily implement the present invention.

FIGS. 1 and 2 are an exemplary diagram and a block diagram showing the construction of an apparatus for measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention. FIG. 3 is a block diagram showing a method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with and embodiment of the present invention. FIGS. 4 and 5 are exemplary diagrams showing a process of measuring a Pantoscopic Tilt (PT) in the state in which glasses are worn and an eye height is fixed in the method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention. FIGS. 6 and 7 are exemplary diagrams showing a change of a head bow angle and the length of a corridor when a PT is positive and negative, respectively, in the method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention.

As shown in FIGS. 1 and 2, an apparatus for measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention includes a near Pupil Distance (PD)apparatus 1 for measuring an angle, height, and direction (tilt) when the subject of measurement grasps a book and asensing apparatus 2 for measuring the face and an angle of a gaze of the subject of measurement who gazes steadily at thenear PD apparatus 1 for reading in an glasses-wearing state and transferring measured result values together with a head bow angle and direction of the subject of measurement to thenear PD apparatus 1 when thesensing apparatus 2 is mounted on the frame of glasses by a jig.

Thenear PD apparatus 1 may calculate a rotation angle of an eyeball (hereinafter referred to as a 'eye rotation angle') according to the measured result values transferred from thesensing apparatus 2.

Thenear PD apparatus 1 is used on the premise that a portable tablet will be used. The portable tablet means a variety of portable computers using a touch screen method, such as iPad based on the IOS, Galaxy Tab based on the Android OS, and a tablet based on Windows, but not limited thereto.

A precondition is that thenear PD apparatus 1 includes all types of devices to which ascreen module 11 configured to have an input/output function, acamera module 12 configured to photograph a surrounding environment in real time, asensor module 13 configured to sense a behavior pattern of the subject of measurement, a Radio Frequency (RF)module 14 configured to perform wireless communication with thesensing apparatus 2, and anoperation module 15 configured to store and/or process pieces of information received from the screen module, the camera module, the sensor module, and the RF module have been applied.

The meaning of the term 'applied' may include both a case where thescreen module 11, thecamera module 12, thesensor module 13, theRF module 14 and theoperation module 15 are embedded in the portable tablet and configured to perform respective functions and a case where one or more of the above-described modules are coupled to thenear PD apparatus 1 in such a way as to be able to be driven and configured to perform the respective functions.

For example, thescreen module 11 has an input/output function according to the manipulation of a user. Thescreen module 11 is commonly disposed in front of the portable tablet. If a screen needs to be enlarged or an output needs to be performed through a display device disposed in another space, an external screen module may be coupled to the portable tablet.

Thecamera module 12 may measure an eye rotation angle by photographing the subject of measurement in real time. Thecamera module 12 is commonly disposed in part of the front or rear of the portable tablet, but an external camera module may be coupled to the portable tablet if more precise photographing is necessary.

Thesensor module 13 may sense a behavior pattern of a user when the user takes a specific action while the user holds the portable tablet and include an acceleration sensor, a gyro sensor, and a level sensor. Thesensor module 13 can sense a variety of behavior patterns of the subject of measurement who holds thenear PD apparatus 1 and parameters, such as an interval between thenear PD apparatus 1 and the surface of the earth and a distance and tilt between a user and the portable tablet.

Theoperation module 15 may store and/or process pieces of information received from thescreen module 11, thecamera module 12, thesensor module 13, and theRF module 14. In addition, theoperation module 15 may store and/or process information stored in the portable tablet itself and information received over a near distance/long distance communication network.

Furthermore, theoperation module 15 may function to generate images of a face angle and an eye rotation angle of the subject of measurement by processing information obtained by thescreen module 11, thecamera module 12, thesensor module 13, and theRF module 14 and information including images for fabricating other user custom-made progressive lenses.

Thesensing apparatus 2 may transmit result values obtained by measuring a face angle and eye rotation angle of the subject of measurement who gazes steadily at thenear PD apparatus 1 in a glasses-wearing state to thenear PD apparatus 1. A precondition is that thesensing apparatus 2 may include all types of devices to which a sensor andRF module 21 configured to measure a head bow angle and direction of the subject of measurement and send result values obtained by the measurement to thenear PD apparatus 1, anoperation module 22 configured to store and/or process information received from theRF module 21, and apower module 23 configured to be supplied with a power source from thenear PD apparatus 1 or embedded battery have been applied.

The meaning of the term 'applied' may include a case where the sensor andRF module 21, theoperation module 22, and thepower module 23 are provided in thesensing apparatus 2 and configured to perform respective functions.

For example, the sensor andRF module 21 may sense behavior patterns of the subject of measurement who has worn glasses, such as a head bow action and a head turn action, in the state in which the sensor andRF module 21 has been mounted on the frame of glasses of the subject of measurement. The sensor andRF module 21 may include an acceleration sensor and a gyro sensor.

Theoperation module 22 may store and/or process information received from the sensor andRF module 21 and also store and/or process information received from the portable tablet over a near distance/long distance communication network.

A method of measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention, as shown in FIG. 3, may include measuring an eye rotation angle for setting the Length Of a Corridor (LOC) in the state in which the subject of measurement has worn thesensing apparatus 2 for measuring face and gaze angles of the subject of measurement associated with thenear PD apparatus 1, along with glasses. The method of measuring an eye rotation angle is basically classified into four steps S110 to S140.

More particularly, the method of measuring an eye rotation angle may include a first step S110 of measuring a head bow angle and direction of the subject of measurement by using thesensor module 21 provided in thesensing apparatus 2; a second step S120 of measuring a head bow angle and direction of the subject of measurement by using thecamera module 12 built in thenear PD apparatus 1 and also measuring an angle, direction, and height of thenear PD apparatus 1 when the subject of measurement reads a book by using thesensor module 13 built in thenear PD apparatus 1; a third step S130 of measuring an eye rotation angle according to a reading habit of a person who wears glasses by measuring a head bow angle, reading angle, and posture of the person who wears glasses; and a fourth step S140 of setting the length of the corridor based on the pieces of information on an eye rotation angle measured in the steps.

Information measured in the first step S110 may include not only information on images of the subject of measurement that have already been captured, but also information on moving images of the subject of measurement that are captured in real time. The pieces of information on the subject of measurement may be stored in theoperation module 15 temporarily or permanently and processed if necessary.

In the second step S120, a variety of behavior patterns of a user face (including an eyeball or the surroundings of the eyeball) may be sensed. For example, thesensor module 13 may obtain information on the distance between the eyeball of a user and thenear PD apparatus 1 by sensing a behavior pattern that the eyeball of the user approaches thenear PD apparatus 1 or the user pulls thenear PD apparatus 1 toward the user in order to check an image (i.e., a focus '+' image) outputted to thescreen module 11.

In this case, information on the distance between the eyeball of the user and thenear PD apparatus 1 may be classified into a near distance, a middle distance, and a long distance and may be used as basic data for fabricating a user custom-made progressive lens image to which refraction power (e.g., myopia, astigmatism, hyperopia, presbyopia, an addition, and an axis) has been applied.

Furthermore, thesensor module 13 may obtain information on the location of a user face by sensing a behavior pattern that a user moves his face up and down or left and right (also called a so-called 'user eye habit' or 'user reading habit') in order to check an image (i.e., a focus '+' image) outputted from thescreen module 11.

In this case, thesensor module 13 may obtain information on a head bow angle of the user by sensing the behavior pattern that the user moves his face up and down and may obtain information on a horizontal movement angle of the head of the user by sensing the behavior pattern that the user moves his face left and right. Furthermore, thesensor module 13 may obtain information on an eye rotation angle of the user and the length of the corridor by comprehensively taking the pieces of obtained information into consideration and use the pieces of obtained information as basic data for fabricating a user custom-made progressive lens to which the eye habit patterns of the user has been applied.

In the third step S120, a precondition includes all reading habits in which a person who wears glasses bows his head or drops his eyes, a person who wears glasses slantingly lies back on a sofa and reads a book, a person who wears glasses reads a book down, and a person who wears glasses takes a book down (i.e., whether or not the person blows his head, whether or not the person drops his eyes, whether or not the person slantingly leans back in a chair and reads a book, whether or not the person reads a book down, and whether or not the person reads a book up).

The apparatus and method for measuring an eye rotation angle for setting the length of the corridor of a progressive lens in accordance with an embodiment of the present invention are described in detail below.

First, referring to FIGS. 4 to 7, if an overall movement angle of a gaze that is oriented downward when a user gazes steadily at a near distance target on the basis of a case where the user gazes steadily at a long distance object or an eye height object, is assumed to be the sum of a head bow angle and an eye rotation angle, the length of a corridor when fabricating a progressive lens may be calculated by measuring the eye rotation angle other than the head bow angle and substituting the measured eye rotation angle in an equation.

To this end, the eye rotation angle is measured and calculated by using a specific program. In the state in which a user wears glasses and gazes steadily at an eye height object, precisely measured Pantoscopic Tilt (PT) (i.e., an angle formed between a vertical line perpendicular to a lateral reference horizontal plane of the subject of measurement and a side line of the spectacle lens as shown in FIGS. 4 and 5) is defined as a first Inclination Angle 1 (hereinafter referred to as an 'IA 1'). In this case, even when only a front shape of the subject of measurement is photographed, the PT may be measured (the first step: S110).

Furthermore, in the state in which a user wears glasses and conveniently sees a gaze point (+) displayed in thescreen module 11 of thenear PD apparatus 1, an angle formed by the front of thenear PD apparatus 1 and the front of the lens of the glasses that are worn by the subject of measurement may be measured and defined as a second Inclination Angle 2 (hereinafter referred to as an 'IA 2') (the second step: S120).

It should be noted that assuming that the subject of measurement conveniently opens a book of about A4 paper in size and sees the book, only a middle part of the book over the book has only to enter a visual field within the lower rim of the frame of the glasses. That is, the user's gaze has only to be met so that the gaze point (+) indicated in the middle part of thescreen module 11 of thenear PD apparatus 1 enters the lower rim of the frame of glasses.

Furthermore, for the precise measurement, the surface of the book may be orthogonal to the user's gaze. In order to meet this condition, the gaze point (+) displayed in the middle part of thescreen module 11 of thenear PD apparatus 1 is made not seen twice or made enter the center of a circle, and then measurement is performed (the third step: S130).

Next, a result value obtained by subtracting the measurement value of the inclination angle (IA 1) from the measurement value of the inclination angle (IA 2) is used as the eye rotation angle. That is, a difference angle between theIA 1 and theIA 2 on the basis of theIA 1 is the eye rotation angle (the fourth step: S140).

For example, as shown in FIG. 4, if both theIA 1 andIA 2 are 7°, it can be seen that a user bows his head without dropping his eyes and gazes steadily at a near distance target and thus an eye rotation angle ic calculated at 0°. On the other hand, as shown in FIG. 5, if theIA 1 is 7°and theIA 2 is -18°, an eye rotation angle is calculated at 25°.

In particular, it can be seen that if a Pantoscopic Tilt (PT) is measured at a near distance target when a user gazes steadily at a near distance on the basis of a Pantoscopic Tilt (PT) having an always specific angle to a face assuming that an eye rotation angle when the user gazes steadily at an eye height long distance is 0, a minus (-) value (i.e., an upper direction) is calculated.

That is, it can be seen that the head is shaken on the basis of the near distance target. In other words, it can be seen that the user less bows his head and gazes steadily at the near distance target. If the user raises his head in the state in which a near distance gaze point has been determined and sees a gaze point, it can be seen that the user drops his eyes as much as the angle that the user raises his head and sees an object.

In contrast, assuming that a total angle of a gaze that moves downward when a user sees a near distance target (i.e., a book) on the basis of a case where the user gazes steadily at an eye height long distance target is 60°, it can be seen that the user has bowed only his head 60° without moving his eyeballs downward as in FIG. 4. A difference angle 25° between inclination angles measured at a long distance and a near distance target orthogonal to the user's gaze can be see as the eye rotation angle as shown in FIG. 5.

As a result, if the above-describe steps S110 to S140 are performed, there are advantages in that a very precise product can be fabricated and a manufacturing time can be significantly reduced in fabricating a special glasses lens, such as a progressive lens that has complicated manufacturing steps and requires a precise test.

Although the some exemplary embodiment of the present invention have been described in detail above, the scope of the present invention is not limited to the specific embodiments and should be interpreted by the attached claims. Furthermore, a person having ordinary skill in the art can modify the present invention in various manners without departing from the category and spirit of the present invention.

Claims (5)

1. An apparatus for measuring an eye rotation angle for setting a length of a corridor of a progressive lens, the apparatus comprising:

   a near Pupil Distance (PD) apparatus for measuring an angle, height, and direction when a subject of measurement who wears glasses grasps a book; and

   a sensing apparatus for measuring angles of a face and a gaze of the subject of measurement when the subject of measurement gazes steadily at the near PD apparatus and transferring measured result values to the near PD apparatus when the sensing apparatus is mounted on a frame of the glasses by a jig.
2. The apparatus of claim 1, wherein the near PD apparatus is configured to calculate an eye rotation angle according to the measured result values transferred from the sensing apparatus.
3. The apparatus of claim 1, wherein the near PD apparatus comprises:

   a screen module configured to have an input/output function;

   a camera module configured to photograph a surrounding environment in real time;

   a sensor module configured to sense behavior patterns of the subject of measurement;

   a Radio Frequency (RF) module configured to perform wireless communication with the sensing apparatus; and

   an operation module configured to store and/or process pieces of information received from the screen module, the camera module, the sensor module, and the RF module.
4. The apparatus of claim 1, wherein the sensing apparatus comprises:

   a sensor and RF module configured to measure a head bow angle and direction of the subject of measurement and send the result values to the near PD apparatus;

   an operation module configured to store and/or process information received from the RF module; and

   a power module configured to supply a power source itself or receive a power source from the near PD apparatus.
5. A method of measuring an eye rotation angle for setting a Length of a Corridor (LOC) of a progressive lens, the method comprising:

   measuring the eye rotation angle for setting the LOC in a state in which a sensing apparatus for measuring face and gaze angles of the subject of measurement have been mounted on glasses,

   wherein measuring the eye rotation angle comprises:

   measuring a head bow angle and direction of the subject of measurement by using a sensor module included in the sensing apparatus;

   measuring a head bow angle and direction of the subject of measurement by using a camera module built in a near PD apparatus for measuring behavior patterns of the subject of measurement and measuring an angle, direction, and height of the near PD apparatus when the subject of measurement reads a book by using a sensor module built in the near PD apparatus;

   measuring an eye rotation angle according to a reading habit of a person who wears the glasses by measuring a head bow angle of the person and an angle and posture when the person reads a book; and

   setting the LOC based on information on the measured eye rotation angle.

Images