Photochromic and polarized lenses promote healthy sight and can make patients safer every day. An ECP’s responsibility starts with kids and is even more important for senior patients. In addition, every optician should know the newest performance and availability of both products.

Photochromics and Healthy Sight
Before describing the performance advantages of Transitions over just clear lenses, it is important to know the healthy aspects of good lens dispensing. Key is to provide a patient with improved vision quality (digitally surfaced lenses, good fitting, the right materials, etc.) and comfort. Glare affects vision quality and eye health. Glare is the excess of light, both visible and invisible ultra-violet radiation. Glare reduces contrast, blurs objects, causes eye fatigue, injures cells, makes for wrinkles, causes cataracts and can be so intense from a reflection that for an instant vision is blinded. All patients should be taught that glare is a problem and the effects of UV are accumulated over a lifetime. Seniors suffer badly from the effects of glare. Lenses that effectively filter glare are essential.

Susan Stenson,MD, in Light, Sight, and Photochromics describes glare as “the loss of visual performance produced by the occurrence of visible light that is greater than the light to which the eyes are adapted”. To ensure that the right amount of light is available to the eye, the ideal lens would change as light intensity changed.



More importantly, invisible UV radiation damages the eye. Photochromic lenses absorb 100% of the UV. Photochromics use UV to trigger their change of density. Two kinds of UV reach the surface of the earth. UVB (290-315 nanometers) causes sunburn and UVA (315-380 nanometers), has been shown to cause cataracts. Also, since UV damage accumulates and does not appear to be reversible, protection should start with kids. Photochromic lenses absorb 100% of the UVB and UVA so they are “like sunscreen for the eyes”.

Ultraviolet radiation and also blue light has been shown to cause cataracts. The cornea is transparent to UV up to ~350nm so lets UV into the eye and to the lens. Absorption by the lens causes fiber and protein change, or additional yellowing and the result is opacity in the lens. Major studies have also shown that cataracts are more common to people and occupations where they are exposed to more sunshine. Therefore, to reduce or slow the incidence of cataracts, wear UV absorbing lenses and start early.

From Transitions, Inc. this table lists eye pathology on a lifetime timeline. As you can see, the majority of damage from UV occurs by the age of 18 so all children should be in UV attenuating lenses. For the non-prescription wearing person, that means UV attenuating sunglasses during the day. In fact, given this evidence, it suggests that clear UV absorbing Plano lenses are a good idea. Transitions would be a very convenient and protective pair of glasses every day.

Age Related Macula degeneration (AMD), is the leading cause of blindness in the older population and some researchers link UV and more recently blue light as causes. Clearly, UV and blue light are problematic and we are able to protect patient’s eyes by using lenses that absorb those wavelengths.

Night vision is also affected by UV absorption during the day. Wearing good UV absorbing sunglasses during the day prevents the over-bleaching of the pigments that the peripheral retina uses for dark adaptation and night vision.

In fact, rarely do patients understand that the inability to dark-adapt when entering a dark movie theater and find a seat might be because they were outdoors all day without good glare protection and “over bleached” their retina. Without good UV absorbing sunglasses during the day, the chemical (rhodopsin) in the rods (night or light vision) that bleaches and releases an electrical signal along the optic nerve to the brain gets over bleached. It cannot regenerate sufficiently. As a result, adapting to the dark takes longer; vision is poorer and may become unsafe. This is more of a problem in senior patients since dark adaptation takes longer as we age. Nothing replaces the flexibility of a photochromic for the daily in and out of everyone’s life.


Photochromic Performance
Transitions are available in virtually all lens styles and lens materials, so no patient should be excluded from being talked to about their benefits. Transitions photochromic dyes cause the lens to darken, when exposed to ultraviolet rays from sunlight. With less UV light lenses fade. As the light conditions change, the level of tint adjusts, offering the right tint at the right time. The lenses always absorb UV so they are automatically protective from UV in both the clear (by material) and darkened states (all materials).

Tell patients that they can wear photochromics as clear lenses, all day, every day. In fact they work just like clear lenses in all situations like driving, at the computer and for movies and TV. Be sure to tell patients that since they change so subtlety, they will sometimes even think that they “aren’t working”. Reassure them and congratulate them on their sophisticated choice of lenses.

 Outdoors photochromic lenses automatically darken depending upon the amount of UV radiation present. The brighter the sun, the darker they get and are as dark as sunglasses. On very hot days, the photochromic dyes will not get as dark. For those patients requiring dark lenses in extreme temperatures, recommend polarized or fixed tint sunglasses. Photochromics always block 100% of both UVA and UVB rays.

Use polycarbonate, Trivex and high index Transitions V with ESP for patients that want improved fade back performance. They fade back in less than half the time. The graph shows how much faster Transitions V with ESP fades back. To better meet expectations, offer patients improved photochromic performance.

 Windshields block most of the UV that darkens photochromics, so they won’t get dark while driving. A better solution for this person is to have a pair of photochromics for everyday wear and a pair of polarized sunglasses for driving. Suggest new Drivewear Lenses by Younger Optics. The are “Activated by Transitions.” These lenses use a high efficiency polarizer and two Transitions photochromic systems; one darkens from visible light, the other from UV. The result is a lens that darkens behind a windshield, as well as outdoors.

Improve a patient’s quality of vision and protect their eyes at the same time. Because photochromics automatically adjust to varying light conditions, they enhance the ability to discern objects of varying size, brightness and contrast, so you see better.

Transitions Lenses are the first to earn the American Optometric Association (AOA) Seal of Acceptance for UV Absorbers/Blockers. Additionally, Transitions Lenses meet internationally recognized standards for UV blockage, including ANSI Z80.3, ISO 8980-3, EN 1836 and AS/NZS 1067.

 

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