Method for Designing a Pair of Opthalmic Lenses and Device for Optical Measurements

Abstract

Method for designing a pair of ophthalmic lenses and device for optical measurements. The method comprises: determining a distance and placing an object (100) at said distance; placing a frame (4) of reference on the user; for each eye: keeping it uncovered and covering the other eye; placing in front of the eye a screen (5, 6) with a through hole (520, 620); shifting the position of the hole (520, 620) until the user sees said object (100) looking through the hole (520, 620), so that said object (100) is centred in the field of view available; uncovering both eyes; adjusting the positions of the holes (520, 620), to obtain binocular vision; and designing each lens (510, 610) according to said position. The device (1) comprises a frame (2) to which, for each eye, a first plate (51, 61) having a vertical groove (53, 63) and a second plate (52, 62) having a horizontal groove (54, 64) are attached and can be shifted. So that, when the grooves overlap, a pinhole (55, 65) is formed.

Claims

1-24. (canceled)

25. Method for designing a pair of ophthalmic lenses (510, 610), each lens (510, 610) corresponding to an eye (500, 600) of a user, comprising a measurement stage comprising the following steps: [a] determining a viewing distance and place a reference object (100) at a point located at said viewing distance; [b] putting a reference spectacles frame (4) on a user, configured to determine a wearing position of said lenses (510, 610); [c] for a first eye (500, 600) of the user: [1] keeping said eye (500, 600) uncovered and covering the other eye (500, 600); [2] placing in front of said eye (500, 600) a screen (5, 6) corresponding to said eye (500, 600), having a through hole (520, 620) corresponding to said eye (500, 600); [3] shifting the position of said hole (520, 620) until the user sees said object (100) looking through said hole (520, 620), so that said object (100) is centred in the field of view that said hole (520, 620) allows; [d] repeating steps [c.1] to [c.3] for a second eye (500, 600); [e] uncovering both eyes; [f] in the event that the user sees, in a dissociated way, two areas corresponding to said holes (520, 620) corresponding to said first eye (500, 600) and to said second eye (500, 600), adjusting the position of said holes (520, 620) so that both images fuse, thus obtaining binocular vision; [g] for each hole (520, 620) corresponding to an eye (500, 600) and to a lens (510, 610), taking a measurement of the position of said hole (520, 620) with respect to said wearing position of said lens (510, 610); and [h] designing each lens (510, 610) corresponding to an eye (500, 600) such that its optical centre for said viewing distance is determined according to said position of said hole (520, 620) corresponding to said eye (500, 600); wherein each one of said holes (520, 620) is a pinhole (55, 65); wherein for each eye (500, 600), said screen (5, 6) for said eye (500, 600) comprises a first plate (51, 61), having a vertical through groove (53, 63), and a second plate (52, 62), overlapping said first plate (51, 61) and having a horizontal through groove (54, 64), so that said pinhole (55, 65) is formed by the overlap between said vertical groove (53, 63) and said horizontal groove (54, 64), and wherein the steps [c] to [f] break down into a stage for determining the horizontal position of said hole (520, 620), comprising the following steps: [c] for a first eye (500, 600) of the user: [1] keeping said eye (500, 600) uncovered and covering the other eye (500, 600); [2] placing said first plate (51, 61) in front of said eye (500, 600); [3] shifting said first plate (51, 61) until the user sees said object (100) looking through said vertical groove (53, 63), so that said object (100) is centred in the field of view that said vertical groove (53, 63) allows; [d] repeating steps [c.1] to [c.3] for a second eye (500, 600); [e] uncovering both eyes; and [f] in the event that the user sees, in a dissociated way, two vertical strips corresponding to said vertical grooves (53, 63), adjusting the position of said first plates (51, 61), so that both images fuse, thus obtaining binocular vision; and a stage for determining the vertical position of said hole (520, 620), comprising the following steps: [c] for a first eye (500, 600) of a user: [1] keeping said eye (500, 600) uncovered and covering the other eye (500, 600); [2] placing said second plate (52, 62) in front of said eye (500, 600), overlapping said first plate (51, 61); [3] shifting said second plate (52, 62) until the user sees the object (100) looking through said pinhole (55, 65), so that said object (100) is centred in the field of view that said pinhole (55, 65) allows; [d] repeating steps [c.1] to [c.3] for a second eye (500, 600); [e] uncovering both eyes; and [f] in the event that the user sees, in a dissociated way, two visual points corresponding to said pinholes (55, 65), adjusting the position of said second plates (52, 62), so that both images fuse, thus obtaining binocular vision.

26. Method according to claim 25, wherein each one of said pinhole (55, 65) has a diameter between 0.2 mm and 5 mm, preferably between 0.4 mm and 0.6 mm, more preferably 0.5 mm.

27. Method according to claim 25, wherein in the event that in points [f], [f] or [f] the user is not able to get both images to fuse, the method further comprises the following additional steps: taking a measurement of the associated phoria for said viewing distance; determining a prism necessary for said associated phoria; repeating the measurement with the presence of said prism; and designing said pair of lenses (510, 610) for said viewing distance also according to said prism.

28. Method according to claim 27, wherein said measurement of said associated phoria is taken in one of the points [e], [e] or [e], or [f], [f] or [f], comprising the following additional steps: placing in front of one of the eyes (500, 600) a prism having a known prismatic power, said prism being overlapped with said hole (520, 620), preferably on the side of said hole (520, 620) furthest from said eye (500, 600); repeating the point above with prism having different prismatic powers until making the images from both eyes (500, 600) fuse; and determining said prism necessary for said associated phoria as the prism that makes the images from both eyes (500, 600) fuse.

29. Method according to claim 28, wherein a colour filter is previously placed in the line of sight of one of said eyes (500, 600), preferably a red filter.

30. Device (1) for optical measurements, comprising a frame (2) having a wearing position wherein a user wears said device (1) in front of the eyes (500, 600), defining an inner side facing said eyes (500, 600), and an outer side opposite to said inner side, said device (1) having first frame supporting means (31, 32, 33), wherein the device also comprises: a right screen (5), corresponding to the right eye (500, 600) of a user, comprising a first right plate (51) and a second right plate (52); and a left screen (6), corresponding to the left eye (500, 600) of a user, comprising a first left plate (61) and a second left plate (62), all said plates (51, 52, 61, 62) being preferably non-transparent and wherein for each one of said screens (5, 6): said first plate (51, 61) is horizontally slidable mounted on said frame (2), and has a vertical through groove (53, 63); said second plate (52, 62) is vertically slidable mounted on said frame (2), and has a horizontal through groove (54, 64); each one of said screens (5, 6) having: a first working position wherein only one of between said first plate (51, 61) and said second plate (52, 62) interferes the line of sight (56, 66) of the eye (500, 600) corresponding to said screen (5, 6); y a second working position wherein said first plate (51, 61) and said second plate (52, 62) interfere the line of sight of the eye (500, 600) corresponding to said screen (5, 6); wherein for said second working position, said vertical groove (53, 63) and said horizontal groove (54, 64) overlap forming a pinhole (55, 65).

31. Device (1) according to claim 30, wherein said first frame supporting means (31) comprise gripping means (31), configured to attach said device (1) to a spectacles frame (4) on said inner side.

32. Device (1) according to claim 30, wherein said first frame supporting means (32, 33) comprise arms (32) which in the wearing position extend towards said inner side, and a nasal support (33), both configured to attach said device (1) to the head of a user.

33. Device (1) according to claim 31, wherein it also comprises second frame supporting means (42, 43), comprising arms (42) and a nasal support (43), said device (1) having a secondary wearing position wherein said arms (42) extend towards said outer side, said second frame supporting means being (42, 43) configured to attach said device (1) to the head of a user from said outer side.

34. 10-Device (1) according to claim 30, wherein said vertical groove (53, 63) has a width between 0.2 mm and 5 mm, preferably between 0.4 mm and 0.6 mm, more preferably 0.5 mm.

35. Device (1) according to claim 30, wherein said horizontal groove (54, 64) has a width between 0.2 mm and 5 mm, preferably between 0.4 mm and 0.6 mm, more preferably 0.5 mm.

36. Device (1) according to claim 30, wherein said first plate (51, 61) is configured to allow, in said first or said second working position, a shift of said vertical groove (53, 63) between 18 mm and 40 mm with respect to the bisecting nasal plane.

37. Device (1) according to claim 30, wherein it also comprises measurement means (57, 58, 67, 68, 77, 78) to determine the position of each one of said grooves (53, 54, 63, 64).

38. Device (1) according to claim 37, wherein said measurement means (57, 58, 67, 68, 77, 78) are, each one independently, one of a list consisting of: a scaled ruler, a vernier or a reference for external measurement device; preferably a vernier.

39. Device (1) according to claim 30, wherein it also comprises right supporting means (59) configured to support at least one optical element (7) in front of said right screen (5).

40. Device (1) according to claim 30, wherein it also comprises left supporting means (69) configured to support at least optical element (7) in front of said left screen (6).

41. Device (1a) according to claim 40, wherein each one of said at least one optical element (7) is, independently, one of a list consisting of: corrective lenses, colour filters or polarizing filters.

42. Device (1a) according to claim 39, wherein each one of said at least one optical element (7) is, independently, one of a list consisting of: corrective lenses, colour filters or polarizing filters.

43. Device (1) according to claim 30, wherein in said first working position, said plate (51, 52, 61, 62) selected from said first plate (51, 61) and said second plate (52, 62) which interferes the line of sight (56, 66) of the eye (500, 600) is said first plate (51, 61).

44. Device (1) according to claim 43, wherein said second plate (52, 62) is tiltable between a position parallel to said first plate (51, 61) for said second working position, and a retracted tilted away position for said first working position.

45. Device (1) according to claim 43, wherein said second plate (52, 62) is shiftable between a position parallel to said first plate (51, 61) for said second working position, and a retracted shifted away position for said first working position, said retracted shifted away position also being parallel to said first plate (51, 61).

46. Device (1) according to claim 45, wherein said frame (2) has a general upside-down U shape, with an upper horizontal section (8), a right vertical section (9) and a left vertical section (10); so that for said right screen (5), said first plate (51) is shiftable along a right zone of said horizontal section (8), and said second plate (52) is shiftable along said right vertical section (9); and for said left screen (6), said first plate (61) is shiftable along a left zone of said horizontal section (8), and said second plate (62) is shiftable along said left vertical section (10).

47. Device (1) according to claim 46, wherein each one of said plates (51, 52, 61, 62) is attached to said frame (2) and is shiftable along it by micrometric adjustment means (11).

48. Device (1) according to claim 46, wherein the position of said right vertical section (9) and the position of said left vertical section (10) can be adjusted horizontally, independently of one another.

49. Device (1) according to claim 47, wherein the position of said right vertical section (9) and the position of said left vertical section (10) can be adjusted horizontally, independently of one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0100] The advantages and characteristics of the invention are appreciated from the following description wherein, in a non-limiting way with respect to the scope of the main claim, some preferred embodiments of the invention are explained, referring to the figures.

[0101] FIG. 1 shows a simplified view of some stages of the method wherein, as a reference, only the spectacles frame and the screens are shown. The dashed lines represent the vision axes.

[0102] FIG. 2 shows a simplified overhead view of a representation of the elements used in the method of the invention. By way of reference, the wearing position of the lenses is shown with dotted lines, as well as the vision axes marked with dashed lines.

[0103] FIG. 3 is a front view of the device according to the invention.

[0104] FIG. 4 is a rear view of the device according to the invention wherein, as an example, the reference frame has been shown with dashed lines.

[0105] FIG. 5 is an overhead view of the device in use. For the sake of clarity, only some relevant references have been marked.

[0106] FIG. 6 is a perspective view of the device of the invention.

[0107] FIG. 7 is a perspective view of an embodiment of the device of the invention able to be worn directly by a user.

[0108] FIG. 8 is a perspective view of another embodiment of the device that comprises both the support for an external spectacles frame and some elements that allow it to be worn directly by a user.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

[0109] FIGS. 1 and 2 show an embodiment of the method for designing a pair of ophthalmic lenses 510, 610. In a first example, said pair of lenses 510, 610 is intended for lenses for near vision, in particular for reading. Each lens 510, 610 corresponds to an eye 500, 600 of a user. Thus, the right lens 510 corresponds to the right eye 500, and the left lens y 610 corresponds to the left eye 600. FIG. 2 represents diagrammatically the future wearing position of the lenses 510, 610 by means of a dotted line. The method comprises a measurement stage comprising the following steps: [0110] [a] Determining a viewing distance, which in the case of the example is for near vision, and place a reference object 100 at a point located at said viewing distance. The object 100 is placed at the predetermined distance and also at an angle which is preferred for the user according to their preferred posture, in this case, the reading posture. Therefore, as an example, the user is asked to position him or herself in their usual reading posture and the reference object 100 is placed in the place where the eyesight must be focused, for example, in the place where the user would place a book for reading it. [0111] [b] Putting a reference spectacles frame 4 on a user, configured to determine a wearing position of said lenses 510, 610. [0112] [c] For a first eye 500, 600 of the user, as an example, for the right eye 500, although the method is equivalent for the left eye 600: [0113] [1] Keeping said eye 500 uncovered and cover the other eye 600, for the example, the action of covering means closing the eye 600 with the eyelids. [0114] [2] Placing in front of said eye 500 a screen 5 corresponding to said eye 500 having a through hole 520 corresponding to said eye 500. In the example shown in FIGS. 1 and 2 the screen 5 is an opaque card and said hole 520 is a pinhole 55 that has a diameter of 0.5 mm. The hole 520 shown in the figures is not to scale, so that it can be clearly distinguished. [0115] [3] Shifting the position of said hole 520 until the user sees said object 100 looking through said hole 520, so that said object 100 is centred in the field of view that said hole 520 allows, in the case of the example, the hole 520 shifts when the screen 5 having the hole is shifted. [0116] [d] Repeating steps [c.1] to [t c.3] for a second eye. In the case of the example, for the left eye 600. The person skilled in the art will understand that the numeric references in steps [c.1] to [c.3] described above must consequently be modified. For example, for the left eye 600 the other eye corresponds to the right eye 500, the screen 6, and the through hole is 620, which is a pinhole 65 that has a diameter of 0.5 mm. [0117] [e] Uncovering both eyes 500, 600, by opening the eyelids. [0118] [f] In the event that the user sees, in a dissociated way, two areas corresponding to said holes 520, 620 corresponding to said first eye 500 and to said second eye 500 adjusting the position of said holes 520, 620, so that both images fuse, thus obtaining binocular vision. In practice and as an example, the adjustment can be for the two eyes 500, 600 at the same time, or the adjustment can be made for each eye 500, 600 separately, which would be equivalent to repeating some of the steps [c] to [e], or a combination of both solutions. The examples in FIGS. 1 and 2 show the moment when binocular vision is obtained. The person skilled in the art will understand that the steps [c] to [f] have to be made without the user modifying his/her relative position in relation to the reference object 100. [0119] In one embodiment, if the user is not able to fuse both images, the method comprises the following additional steps: [0120] Taking a measurement the associated phoria for said viewing distance. [0121] Determining a prism necessary for said associated phoria. [0122] And repeating the measurement with the presence of said prism, returning to step [c]. [0123] In this case, the design of the pair of lenses 510, 610 for the viewing distance is done also according to said prism. [0124] [g] For each hole 520, 620 corresponding to an eye 500, 600 and to a lens 510, 610, taking a measurement of the position of said hole 520, 620 with respect to said wearing position of said lens 510, 610. In the exemplary embodiment, the measurement is directly taken according to the position of each hole 520, 620 with respect to the frame 4. Alternatively, in other embodiments the spectacles frame 4 includes reference lenses, for example lenses with no correction power. In this case, a preferred embodiment is to mark on each reference lens the position of the corresponding hole 520, 620, and then measuring the position of the point marked on each lens. [0125] [h] Design each lens 510, 610 corresponding to an eye 500, 600 for said viewing distance according to said position of said hole 520, 620 corresponding to said eye 500, 600. In the example, the lenses are monofocal lenses 510, 610 for near vision, and their optical centres will be located according to the measured position of said holes 520, 620.

[0126] Other embodiments of the method according to the invention are shown below which share a large part of the characteristics described in the preceding paragraphs. Therefore, hereinafter only the differentiating elements will be described, while for the common element reference will be made to the description of the first embodiment.

[0127] In another embodiment, said viewing distance corresponds to far vision, so the reference object 100 is placed at a point located in the optical infinity. The person skilled in the art will understand that in the art, in the case of human vision, said optical infinite corresponds to distances starting from 5 m. Therefore, in this example, monofocal lenses 510, 610 are designed for far vision.

[0128] In yet another embodiment, the method is carried out first for a first viewing distance, corresponding to far vision, such as the one described above; and secondly for a second viewing distance, corresponding to near vision like the one described in the first example. So, bifocal lenses 510, 610 are designed with two optical centres: one for far vision and one for near vision, each one the result of repeating the method described above. In an example, the lenses 510, 610 are of the type known as progressive bifocal lenses, so that the relative position between both optical centres determines the inset and the length of the corridors of each lens 510, 610.

[0129] Another embodiment of the method of the invention uses device 1 shown in FIGS. 3 and 4. In this example, for each eye 500, 600, said screen 5, 6 for said eye 500, 600 comprises a first plate 51, 61, having a vertical through groove 53, 63, and a second plate 52, 62, overlapping said first plate 51, 61 and having a horizontal through groove 54, 64, so that said pinhole 55, 65 is formed by the overlap between said vertical groove 53, 63 and said horizontal groove 54, 64. In the example, all the grooves have a width of 0.5 mm, so that the resulting pinhole 55, 65 in the example has a square profile wherein each side measures 0.5 mm. This way, the right screen 5, comprises a first right plate 51, having a right vertical groove 53. Said first right plate 51 is shiftable in the horizontal direction, so that the shifting of plate 51 serves to position the groove 53.

[0130] In addition, the right screen 5 also comprises a second right plate 52, which in the working position overlaps the first right plate 51. The second right plate also having a right horizontal groove 54 which when it overlaps the right vertical groove 53 forms a right pinhole 55. The device 1 allows the vertical movement of the second right plate 52, used to position the right horizontal groove 54. The description is equivalent for the left screen 6.

[0131] In this embodiment, the steps [c] to [f] break down into a stage for determining the horizontal position and a stage for determining the vertical position. In a preferred embodiment, first the stage for determining the horizontal position is carried out and then the stage for determining the vertical position. In another embodiment, the order is reversed. In some embodiments, the method starts with the user's dominant eye. For the sake of clarity, the example described below considers that the initial eye is the right eye 500, although a person skilled in the art will understand that the method is equivalent if starting with the left eye 600.

[0132] Therefore, the stage for determining the horizontal position comprises the following steps: [0133] [c] For a first eye 500 of the user, as an example, the right eye 500: [0134] [1] Keeping said eye 500 uncovered and cover the other eye 600. In particular, the user closes his/her eyes with his/her eyelids. [0135] [2] Placing said first plate 51 in front of said eye 500. [0136] [3] Shifting said first plate 51 until the user sees said object 100 looking through said vertical groove 53, so that said object 100 is centred in the field of view that said vertical groove 53 allows. In a preferred embodiment, the first plate 51 shifts from a position away from a bisecting nasal plane, in the direction of said plane, which favours locating the object 100 since the vertical groove 53 shifts in the same direction as the eyes when they converge. [0137] [d] Repeating steps [c.1] to [c.3] for a second eye 600, in the case of the example, for the left eye, using the elements corresponding to said left eye 600. [0138] [e] Uncovering both eyes. [0139] [f] In the event that the user sees, in a dissociated way, two vertical strips corresponding to said vertical grooves 53, 63, adjusting the position of said first plates 51, 61, so that both images fuse, thus obtaining binocular vision. In some embodiments, if the user is not able to fuse both images, the method comprises the additional steps of measuring the phoria described above. In that case, in some embodiments, the method comprises the additional following steps: [0140] Placing in front of one of the eyes 500, 600, as an example, in front of the right eye 500, a prism having a known prismatic power, said prism overlapped with said hole 520, on the side of said hole 520 furthest from said eye 500. [0141] Repeating the above point with prism having different prismatic powers until making the images from both eyes 500, 600 fuse by adjusting, if it necessary, the position of the vertical grooves 53, 63. [0142] Determining said prism necessary for said associated phoria as the prism that makes the images from both eyes 500, 600 fuse.

[0143] On the other hand, the stage for determining the vertical position comprises the following steps: [0144] [c] For a first eye 500 of a user, as an example, the right eye 500: [0145] [1] Keeping said eye 500 uncovered and covering the other eye 600. [0146] [2] Placing said second plate 52 in front of said eye 500, overlapping said first plate 51. [0147] [3] Shifting said second plate 52 until the user sees the object 100 looking through said pinhole 55, so that said object 100 is centred in the field of view that said pinhole 55 allows. [0148] [d] Repeating the steps [c.1] to [c.3] for a second eye 600, as an example, the left eye 600. [0149] [e] Uncovering both eyes. [0150] [f] In the event that the user sees, in a dissociated way, two visual points corresponding to said pinholes 55, 65, adjusting the position of said second plates 52, 62, so that both images fuse, thus obtaining binocular vision. In some embodiments, if the user is not able to fuse both images, the method comprises the additional steps of measuring the phoria described above.

[0151] In some embodiments where the user has phoria, to measure it, previously in the method a colour filter is placed in the line of sight of one of said eyes 500, 600, preferably a red filter.

[0152] In an embodiment shown in FIGS. 3 and 4, a device 1 is provided for optical measurements, comprising a frame 2 having a wearing position wherein a user wears said device 1 in front of the eyes 500, 600, defining an inner side facing said eyes 500, 600, and an outer side opposite to said inner side, with said device 1 having first frame supporting means 31, which in the case of the example comprise gripping means 31, configured to attach said device 1 to a spectacles frame 4 on the inner side of the device, i.e., the side closest to the user. FIG. 4 shows the front part of said frame 4 with dashed lines.

[0153] The exemplary device 1 also comprises: [0154] A right screen 5, corresponding to the right eye 500, 600 of a user, comprising a first right plate 51 and a second right plate 52. [0155] A left screen 6, corresponding to the left eye 500, 600 of the user, comprising a first left plate 61 and a second left plate 62.

[0156] All said plates 51, 52, 61, 62 being made of a non-transparent material.

[0157] Also, for each of said screens 5, 6: [0158] Said first plate 51, 61 is horizontally slidable mounted on said frame 2, and has a vertical through groove 53, 63. [0159] Said second plate 52, 62 is vertically slidable mounted on said frame 2, and has a horizontal through groove 54, 64.

[0160] In the case of the example, all the plates 51, 52, 61, 62 have a thickness of 0.5 mm, and all the grooves 53, 54, 63, 64, have a width of 0.5 mm.

[0161] Each of said screens 5, 6 having: [0162] A first working position wherein only one of between said first plate 51, 61 and said second plate 52, 62 interferes the line of sight 56, 66 of the eye 500, 600 corresponding to said screen 5, 6. In the exemplary embodiment shown in FIGS. 3 to 8, this corresponds to said first plate 51, 61, therefore the horizontal position of the grooves 53, 63 is measured in the first working position. [0163] A second working position wherein said first plate 51, 61 and said second plate 52, 62 interfere the line of sight 56, 66 of the eye 500, 600 corresponding to said screen 5, 6.

[0164] Therefore, for said second working position of the exemplary device 1, each of the vertical grooves 53, 63 and its corresponding horizontal groove 54, 64 overlap forming a pinhole 55, 65.

[0165] In the same way, in the exemplary embodiment shown in the FIGS. 3 and 4, said second plate 52, 62 is shiftable between a position parallel to said first plate 51, 61 for said second working position, and a retracted shifted away position for said first working position. Said retracted shifted away position also being parallel to said first plate 51, 61. FIG. 3 shows direction arrows that indicate the movement of each plate.

[0166] FIGS. 3 and 4 show a device 1 is provided with a frame 2 having a general upside-down U shape, with an upper horizontal section 8, a right vertical section 9 and a left vertical section 10. So, for said right screen 5, said first plate 51 is shiftable along a right zone of the horizontal section 8 by micrometric adjustment means 11 that attach it to said upper horizontal section 8. Besides, said second plate 52 is shiftable along the right vertical section 9 by micrometric adjustment means 11 that attach it to said right vertical section 9. Likewise, for said left screen 6, said first plate 61 is shiftable along a left zone of said horizontal section 8 by micrometric adjustment means 11 that attach it to said upper horizontal section 8. Also, said second plate 62 is shiftable along the left vertical section 10 by micrometric adjustment means 11 which attach it to said left vertical section 10. For the device 1 in the example, each one of the first plates 51, 61 is configured to allow, in the first or the second working position, a shift of its respective vertical through groove 53, 63 between 18 mm and 40 mm with respect to the bisecting nasal plane.

[0167] In order to adjust the size of the device 1 for different users, the position of the right vertical section 9 and the position of the left vertical section 10 can be adjusted horizontally, independently of one another.

[0168] The device 1 shown in FIG. 3 also comprises measurement means 57, 58, 67, 68 for determining the position of each one of said grooves 53, 54, 63, 64. In the case of the example, a simplified view of a vernier is shown for each one. As an example, FIG. 3 also shows another possible measurement means 77, 78, which in this case comprises a reference for an external measurement device, in particular a small hole 77, 78 into which a caliper can fit.

[0169] Other embodiments of the device 1 according to the invention are shown below that share a large part of the characteristics described in the paragraphs above. Therefore, hereinafter only the differentiating elements will be described, while for the common elements reference is made to the description of the first embodiment.

[0170] In the embodiment shown in FIG. 6 the device 1 comprises right supporting means 59 configured to support at least one optical element 7 in front of said right screen 5, and also left supporting means 69 configured to support at least one optical element 7 in front of said left screen 6. Each optical element in the example is, independently of each other, a corrective lens, a colour filter, for example, a red filter, or a polarizing filter. The person skilled in the art will understand that the list described above is not exclusive and can be extended to all kinds of optical elements, which adds versatility to the device 1. For example, the possibility of adding red filters allows using the device for phoria measurements.

[0171] FIG. 7 shows another embodiment of the device 1 wherein the first frame supporting means 32, 33 comprise arms 32 which, in the wearing position, extend towards the inner side, and a nasal support 33. Both configured to attach said device 1 to the head of a user. It can be appreciated that it takes the shape of a spectacles frame. The arms in the example are collapsible, so that they can be folded onto themselves, and also extendable so that they can adapt to different user morphologies.

[0172] The example in FIG. 8 shows yet another embodiment wherein two types of frame supporting means are combined, one on each side of the device. So the device 1, as well as first frame supporting means in the form of gripping means 31 for attaching the device 1 to a spectacles frame 4, equivalent to FIG. 3 and FIG. 4, also comprises second frame supporting means 42, 43, comprising arms 42 and a nasal support 43, said device 1 having a secondary wearing position wherein said arms 42 extend towards said outer side. Said second frame supporting means 42, 43 being configured to attach said device 1 to the head of a user from said outer side. The person skilled in the art will understand that exchanging the position of both frame supporting means is an equivalent solution to the one described here. As an example, in FIG. 8 the arms 42 of the second frame supporting means are shown in the folded position.

[0173] In another embodiment of the device 1 each second plate 52, 62 of the device 1 is tiltable between a position parallel to its corresponding first plate 51, 61, for the second working position, and a retracted tilted away position for the first working position.

[0174] The embodiments described herein represent non-limiting examples, so that a person skilled in the art will understand that beyond the examples shown, multiple combinations of the claimed characteristics are possible within the scope of the invention.