Unfortunately, many Canadians remain unaware of the danger that ultraviolet (UV) radiation poses to their eyes. As a result, people often don’t take the necessary steps with respect to eye care and protection to ensure that their eyes are safe from the dangers of UV.
In many respects, this lack of knowledge regarding the need for eye protection from UV is somewhat understandable: the human eye can’t perceive UV light as it does visible light (which, along with UV, is a form of electromagnetic radiation emanating from the sun). So many remain blissfully and dangerously unaware of the health risks from UV exposure.
The health risks of UV light to the eye are numerous. Exposure to UV, especially to particular wavelength bands defined as UV-A and UV-B, has been linked to vision loss and a number of eye diseases. These include cataracts, pterygium and pinguecula, lid cancers and macular degeneration.
Cataracts involve the clouding of the lens of the eye, which can, if severe enough, lead to a decline in vision and even blindness. To this point, the Mayo Clinic compares the experience of seeing with cataracts to “looking through a frosty or fogged-up window.” While cataracts can be treated in most cases, sufficient eye protection can help mitigate the risk of developing cataracts in the first place and thereby avoiding eye surgery needed to restore vision secondary to visually significant cataract development.
Pterygium can be similarly pernicious. Unlike cataracts, however, pterygium is a tissue growth that starts on the conjunctiva and progresses to involve the cornea. While frequently benign, this growth can distort vision and cause eye irritation; at that stage, surgery is needed to remove the growth. Pterygium often start out as their more common cousin, pinguecula, which most often grow on the nasal side of the eye where more UV exposure occurs.
Macular degeneration is another potentially sight-threatening disease that can be caused by exposure to UV. Macular degeneration is a major cause of vision loss and blindness for people over the age of 60. Macular degeneration occurs when the macula (the central part of the retina) begins to deteriorate, leading to one of two forms of macular degeneration: wet or dry. The latter tends to be less severe, but also irreversible.
Thankfully, there are ways to reduce the chances of ever having to experience these eye diseases and the accompanying vision loss. Sunglasses are the best bet in this respect, as their lenses can effectively block harmful UV rays from reaching the ocular structures. Sunglasses are therefore indispensable to eye care and eye protection, and they are not just for summer use. When purchasing sunglasses, look for a label that says 100% protection against both UVA and UVB or 100% protection against UV400. The UV400 designation means the lenses will block radiation equal to or shorter than 400 nanometers, which covers both UVA and UVB rays. Sunglasses that offer this protection may differ in the color or intensity of the tint, their overall size and in the quality of the optics they deliver.
As an aside, I want to clear up some terms that are often misunderstood. Transitions lenses, which are protective against UV light, are a brand of photochromic lenses that change color or transition to sunglasses when exposed to UV radiation. Photochromics are the general term for this category of lens. Another brand of photochromics is Sensity, manufactured by Hoya. They perform exceptionally well in all temperature ranges, meaning they will transition to sunglasses just as well under cold conditions. Progressive lenses, which are often confused with Transitions are lenses that progress from far vision towards the top of the lens, to a reading or near vision focus towards the bottom of the lens. They are often referred to as invisible bifocals, but this is truly a misnomer as there are more than two focal lengths delivered by progressive lenses. This fact makes them visually superior in most cases to lined bifocal lenses. Polarized lenses are also often misunderstood. This is a class of sunglasses that have an additional filter to remove light that is reflected from horizontal surfaces, providing better vision due to their ability to reduce glare.
Some contact lenses advertise their ability to block UV rays. This is an added bonus or feature but should not be thought of as a replacement to sunglasses. The reason, they do not cover or protect the conjunctival and scleral tissues, nor do they protect the eyelids. Lid cancers are relatively common and can be both benign and malignant, which means they can spread to other parts of the body. Any new lid growth or lesion that bleeds should be examined.
Come into our eye clinic and consult with Dr. Jeff Sciberras, an eminent Optometrist in Mississauga, to help you find some of the best sunglasses for UV protection. Dr. Sciberras’ guidance and expertise will help you find what’s needed for optimal vision correction and eye protection! Book an appointment online now or contact us for more information on our eye care services.
In honor of July being UV Awareness Month, we are currently running a fantastic promotion on Hoya Sensity photochromic lenses. Call us at 905-828-2282 for more details or to book your next comprehensive eye exam.