TWI768481B - Contact lens having photochromic zone - Google Patents

Abstract

A contact lens includes a first photochromic zone and a second photochromic zone. The photochromic zone is located in the center of the contact lens. The second photochromic zone surrounds the first light Chromogenic zone. Under the same illumination condition, the average transmittance of the first photochromic zone to visible light after photochromic is lower than the average transmittance of the second photochromic zone to visible light after photochromic.. It can be used to alleviate the visual problems caused by sudden changes in environmental illumination.

Description

Contact lenses with photochromic zones

The present invention relates to a contact lens, and more particularly, to a contact lens having a plurality of photochromic regions.

Many people experience glare in brightly lit environments, and photochromic lenses can improve this problem. They become darker in outdoor lighting and reduce light penetration. When returning to indoor environments, photochromic lenses The lens will gradually return to transparency, allowing more light to pass through the lens. In addition to general eyeglasses, photochromic lenses are also used in the field of contact lenses.

However, the existing photochromic lenses are inconvenient or even dangerous in that when a user suddenly enters a weakly illuminated environment from a strong light environment, the photochromic lens cannot immediately complete the color change, resulting in a period of time when the eye cannot receive it. Enough light, so that the user can not see the situation in front of them. Such a situation is common in an environment where the light intensity changes drastically when riding a bicycle, driving into a tunnel, underpass, or basement during the day. At this time, the user is likely to be unable to grasp the road conditions in time due to poor vision, increasing the probability of things happening.

In view of this, the main purpose of the present invention is to provide a photochromic contact lens that can slow down the influence of vision due to sudden changes in ambient illuminance.

In order to achieve the above and other objects, the present invention provides a contact lens with a photochromic area, which includes a first photochromic area and a second photochromic area, the first photochromic area is located in the center of the contact lens, The second photochromic area surrounds the first photochromic area; wherein, under the same lighting conditions, the average transmittance of visible light in the first photochromic area after photochromic is lower than that of the second photochromic area Average transmittance of visible light after photochromic.

Through the above design, when the user is in a strong light environment, the pupil will be reduced, the first photochromic area located in the center of the contact lens can absorb more light, and the second photochromic area at the periphery of the contact lens can absorb a small amount of light from outside the pupil. Light entering from the edge, but overall, it can maintain eye comfort and reduce the user's photophobia. When entering an environment with insufficient light, the human pupil will rapidly dilate. At this time, more light can enter the pupil from the second photochromic area with higher light transmittance, thereby greatly alleviating the problem that the user instantly feels that the environment is too dim.

Please refer to FIG. 1, which is one embodiment of a contact lens having a photochromic region of the present invention, which includes a first photochromic region 10, a second photochromic region 20 and a non-photochromic region Chromogenic zone 30 . The contact lenses are, for example, soft shadow lenses. The first and second photochromic regions 10, 20 are made of photochromic materials, which can reversibly change their chemical substances between two forms by absorbing electromagnetic radiation (mainly light, such as UV light) , and the two forms have different absorption spectra.

The first photochromic area 10 is located in the center of the contact lens, the second photochromic area 20 surrounds the first photochromic area 10, and the non-photochromic area 30 surrounds the second photochromic area 20. connected. Wherein, under the same lighting conditions, the average transmittance of visible light after the first photochromic area 10 is photochromic is lower than the average transmittance of visible light after the second photochromic area 20 is photochromic, and also That is, the first photochromic region 10 is more capable of blocking visible light penetration than the second photochromic region 20 . In a possible embodiment, the average transmittance of visible light in the first photochromic region 10 after photochromic is between 40-90%, and the average transmittance of visible light in the second photochromic region 20 after photochromic The transmittance is between 50-95%. In a possible embodiment, the average transmittance of visible light in the first and second photochromic regions 10 and 20 after photochromic is respectively 40-60% and 80-90%, that is, one blocks light. The first photochromic region 10 with strong ability is matched with a second photochromic region 20 with weak light blocking ability. In a possible embodiment, the outer diameter of the first photochromic region 10 is between 2-3 mm, and the outer diameter of the second photochromic region 20 is between 3-8 mm.

Please refer to FIG. 2 , the user wears the aforementioned contact lens and the first and second photochromic regions 10 and 20 are not yet photochromic. At this time, the entire contact lens is transparent or pale.

Please refer to Figure 3, when the user is in a strong light environment, the user's pupil 1 is reduced (for example, to a diameter of 2-4 mm), the first and second photochromic areas 10 and 20 are photochromic to reduce the luminous flux, The first photochromic area 10 in the center can greatly reduce the amount of light entering the pupil 1 , so that the user does not feel dazzling, and the second photochromic area 20 helps shield the light from the outer edge of the pupil 1 . Where possible, the pupil may be constricted to be smaller than the first photochromic zone.

Please refer to Figure 4, when the user suddenly enters a weak light environment, the first and second photochromic areas 10 and 20 are not yet discolored, and the human pupil 1 is naturally enlarged (for example, to a diameter of 3-8 mm). ), since the second photochromic region 20 originally allows a higher luminous flux, the enlarged pupil 1 can get more light compensation, avoiding or at least greatly reducing the problem of blurred vision, thereby ensuring road safety. Where possible, pupil 1 may be enlarged larger than the second photochromic zone.

It should be noted that, in other possible embodiments, the contact lens may also have no non-photochromic area at all. In other possible embodiments, the contact lens has other photochromic regions in addition to the first and second photochromic regions.

1: Pupil 10: The first photochromic zone 20: Second photochromic zone 30: Non-photochromic area

FIG. 1 is a perspective view of one embodiment of the contact lens of the present invention.

Figures 2 to 4 are schematic diagrams of the use state of an embodiment of the contact lens of the present invention, wherein the circular dotted line with a smaller diameter represents the pupil, and the circular dotted line with a larger diameter represents the iris.

10: The first photochromic zone

20: Second photochromic zone

30: Non-photochromic area

Claims (6)

A contact lens having a photochromic zone, comprising: a first photochromic region located in the center of the contact lens; and a second photochromic region surrounding the first photochromic region; Wherein, under the same lighting conditions, the average transmittance of visible light after the first photochromic region is photochromic is lower than the average transmittance of visible light after the second photochromic region is photochromic. The contact lens with a photochromic region as claimed in claim 1, wherein the outer diameter of the first photochromic region is between 2-3 mm. The contact lens with a photochromic region as claimed in claim 1, wherein the outer diameter of the second photochromic region is between 3-8 mm. The contact lens with a photochromic region according to claim 1, wherein the average transmittance of visible light of the first photochromic region after photochromic is between 40-90%. The contact lens with a photochromic region as claimed in claim 1, wherein the second photochromic region has an average transmittance of visible light between 50-95% after photochromic. The contact lens with a photochromic region as claimed in claim 1, further comprising a non-photochromic region surrounding the second photochromic region.

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