Will I damage my eyes if I don’t wear sunglasses?
Did you know it's just as important to protect your eyes from the sun's harmful rays as it is to shield your skin?
Carnival is almost here! We spend hours out in the hot, scorching sun and many of us don't think about what extended time in the sun can do to our eyes! While briefly exposing an unprotected eye to UV rays usually won't cause any symptoms, prolonged or intense UV exposure without eye protection (including to the sun, welder's arcs and snow ... if your in a cold country. Can cause a condition called photokeratitis.
This can be thought of as sunburn of the cornea, the clear window on the front of the eye. UV rays cause death of the outermost layer of cells of the cornea. Yes, I said death! This results in severe pain affecting both eyes, which begins six to 12 hours after exposure.
Treatment involves oral painkillers and antibiotic eye ointments (to prevent infection of the damaged cornea) while waiting for the corneal cells to regenerate.
The process of regeneration takes 24 to 72 hours and people can expect a full recovery with no complications from photokeratitis. So don't worry too much.
However, repeated exposure to UV radiation without adequate eye protection can result in permanent eye damage. Eye diseases associated with chronic UV exposure include the following.
Here, the normally transparent lens of the eye becomes cloudy. This causes blurred vision and eventually blindness if untreated. It is estimated up to 20% of cataract cases are caused or made worse by UV exposure.
Wearing sunglasses remains one of the most effective ways of preventing cataract formation.
When they cause troublesome visual impairment, cataracts require surgical extraction. In Trinidad, there are thousands of people who currently need cataract surgery and many who do not recognize that they have cataracts.
This is a benign growth of conjunctival tissue on the cornea. The conjunctiva is the transparent membrane overlying the sclera (the white part of the eye) and usually does not cover the cornea. Although non-cancerous, the presence of a pterygium can cause chronic irritation, redness and inflammation.
Pterygia grow slowly over months and years and can obstruct vision when they grow over the pupil. They may also induce astigmatism (an improper curvature of the cornea), which blurs vision.
Treatment for mild pterygia not affecting vision involves lubrication with artificial tears. Those that affect vision may require surgical excision.
Again, chronic UV exposure to unprotected eyes is a major cause of pterygium development.
This is a degenerative disease affecting the central part of the retina (the macula) responsible for central vision. Macular degeneration may result in severe visual impairment.
Treatment comprises injections of medications directly into the eye and aims to limit disease progression; it cannot reverse damage that has already occurred.
While the link between UV exposure and macular degeneration is less clear than with cataracts or pterygia, short-wavelength radiation and blue light (present in bright sunshine) cause damage to the retina. There is a correlation between light exposure and macular degeneration. The harmful blue light is also present in tablets, computers and phones.
Wearing sunglasses is therefore important to limit excessive light exposure of the retina.
Although less common, chronic UV exposure is associated with increased rates of certain types of eye cancers. These are: squamous cell carcinoma of the conjunctiva, melanoma within the eye, and skin cancers of the eyelid and around the eye where people do not routinely apply sunscreen.
Treatment of these cancers may sometimes require surgical removal of the entire eye.
Climatic droplet keratopathy
This is a rare disease caused by UV exposure in which the cornea becomes cloudy, obstructing vision and potentially requiring a corneal transplant to restore vision.
What kind of sunglasses should I wear?
All sunglasses sold with any UVA and UVB protection. What are these?
UV-A results in skin tanning. UV-B has a very high penetrating ability and results in sunburn. Prolonged exposure is responsible for some types of skin disease, skin ageing and cataracts.
It's important to note price is not an indicator of effectiveness in UV protection. Effective sunglasses should be close-fitting and wrap-around to minimize the amount of UV radiation that can reach the eye.
Some contact lenses and most advanced eyeglass lenses also contain UV filters. However, contact lenses only cover the cornea, they provide no protection against the development of pterygia or cancers on or around the eye.
WHEN SHOULD I WEAR THEM?
Sunglasses should be worn at all times when outdoors during the day when the UV index is 3 or above as there is no defined "safe level" of eye exposure to UV radiation. Mind you, since sunglasses from North Shore Optical are so amazing... you can wear them all the time!
They should also be worn regardless of cloudiness, as more than 90% of UV rays can penetrate through cloud. UV rays also reflect off sand and water. The daily peak period of UV exposure is between 10am and 2pm; seeking shade during these hours is preferable.
The eyes of children are particularly susceptible to UV radiation, so children should be encouraged to wear sunglasses as soon as they can tolerate them.