WHAT THE SUN CAN DO TO OUR EYES
We all know that if we plan a day at the beach one of the essential things to bring is sunscreen. Yet not everyone thinks of UV protection for their eyes. After spending 8 hours on the beach without any sunscreen on we can definitely feel the burns on our skin, but we can’t feel our eyes burning if we don’t wear sunglasses.
We have no pain receptors on our eyeballs that react to overexposure to UV, so we don’t feel the damage like we would if we laid out in the sun without any sunblock on. So what does happen over time with multiple exposures to sunlight? What does sun damage to the eye look like?
Ultraviolet light (UV) that comes from the sun hits our skin cells and starts a cascade of events on the molecular level. I won’t get into the details but UV damage causes mutations at the level of our genome, that’s the stuff that dictates how our cells function. The more UV damage to our skin, the more damage we get, yes it is additive. The worst part about it is that our genome gets passed down, so as damaged cells replicate they produce more damaged cells. That is why sun damage in our childhood is so important.
So where can this cell damage happen in our eye?
To start our eyelids are made of thin skin tissue, and just like our skin damage at this level can cause skin cancer. The white part of our eyeball is called the sclera and it too is partly made of skin tissue and can also grow cancerous lesions. Apart from those you can get benign lesions, these don’t turn into cancer but can cause dryness or even a change in your prescription. The first is a pinguecula, which is a thickening of the front surface of the eye, and the second is a pterygium which can cause scarring and disfiguration of the front surface of the eye.
Ultraviolet light can even get all the way into your eyeball. The first structure it hits is the lens of your eye which is part of a system of structures that allow you to see clearly. Over time UV damage to the lens causes it to yellow making it harder and harder to see. This is called a cataract, and the progression of these can be slowed down by wearing UV protectant sunglasses.
Once UV light gets past the lens it can cause damage to the tissue at the very back of our eye called the retina. The retina is the tissue that processes light and allows us to see. The most important part is called the macula, this tiny area in the retina does all our central vision. UV light damages the cells behind the macula, causing debris to build up. As debris builds up we get distortions in our central vision. This is called Age-Related Macular Degeneration. Once the damage has occurred, the vision loss is irreversible.
Some individuals are genetically predisposed to macular degeneration which added onto the UV damage can cause quick progression of the disease. Distortions in our central vision causes difficulty with driving, reading and even recognizing faces.
At the back of the eye we can commonly see freckles. Just like freckles on our skin these pose a greater risk to becoming cancerous with increasing UV damage.
High exposure to UV in a short period of time can even cause burns at the level of the cornea. This can happen in instances like skiing without UV protective goggles, or using tanning beds without UV protection. These burns are very painful and can even lead to permanent scarring if not healed properly.
The most important thing to know when it comes to UV damage is that we cannot undo damage that has already been done. Preventative care is the most important. The majority of our UV damage occurs before adulthood. Children in general spend more time outdoors and are more exposed to UV. The damage is also additive so each exposure to UV will create more damage that adds onto the damage that was created at the last exposure.
So what can you do to prevent UV damage?
UV protectant sunglasses are the most important thing you can do to prevent damage to your eyes. UV sunglasses should be worn all year around, the amount of UV in the winter is just as detrimental as it can bounce off of snow. All children should be wearing a pair of sunglasses to limit the amount of damage over a longer period of time. There are even contact lenses on the market that have UV protection built into them, although they do not protect you from damage to the surfaces around the eyeball like a pair of sunglasses would.
To determine the level of UV damage occurring to your eye be sure to visit your local optometrists. Our instruments can pick up small growths that occur and your optometrist will monitor to see if these start to get larger, change in colour or become suspicious. They’ll be able to take a look at your lenses to evaluate the progression of any cataracts that may be forming. Newer equipment like OCT imaging can assess the level of damage at the macula and can help with earlier diagnosis and more efficient management of macular degeneration.