Sun Damage
SUN DAMAGE
The sun emits both Visible Light, and Ultraviolet (UV) Radiation. UV radiation has three different forms:
UVA: the longest wavelength of the three types of UV, this form reaches the earth's surface (and therefore our bodies) the most. UVA penetrates deepest into the skin & eyes; it goes beneath the surface layer of our tissues - for your eyes, this means it affects the lens in your eye as well as the surface layers.
UVB: most of the sun's UVB is filtered by the atmosphere & ozone layer, however, the amount that does get through can cause damage to the surface layers of your body - mainly your skin, and for your eyes, this would be the conjunctiva & cornea.
UVC: the shortest wavelength and highest frequency of the three types of UV, this is the most damaging. However, it is completely absorbed by the earth's atmosphere so does not contribute to the sun damage to our bodies or eyes.
SUN DAMAGE EFFECTS ON YOUR EYES
PTERYGIUM: continued sun exposure can cause one of the most common forms of damage to the eyes; a Pterygium. A pterygium is the growth of the protective membrane on the outside of the eye, called the Conjunctiva. When this becomes repeatedly targeted by UV light, it becomes inflamed and grows towards the cornea. Pterygiums can cause itchy, gritty, watery eyes, as well as redness when it becomes particularly inflamed. If it keeps growing, it can start to affect vision by inducing astigmatism.
TREATMENT: protecting your eyes from the sun by wearing sunglasses and a hat can slow down the pterygium’s growth, however, if it continues to grow or starts to affect your vision the treatment for pterygium is surgical removal.
KERATITIS: aka inflammation of the cornea. Exposure to high amounts or long periods of UV light can cause a "sunburn" on your cornea. This is most common from light reflecting off the water, light reflecting off snow, or from using tanning beds.
TREATMENT: depending on the inflammation, the usual course of action is to simply let the body heal itself, however, eye drops can be prescribed to aid this healing and protect the eye from getting an infection in the meantime depending on the state of the cornea.
CATARACT: cataract development is inevitable, however, it can be sped up significantly by UV entering the eyes. This is because UV light causes additional oxidative stress to the cells in the lens, causing changes to their cellular structure and therefore making the lens cloudy.
TREATMENT: cataract development can be slowed by protecting your eyes from the sun (i.e. sunglasses), however, any change is irreversible so once the cataract is bad enough that it is affecting your sight the treatment is surgical removal.
SKIN CANCERS: As much as the eyes, the eyelids are also vulnerable to the effects of UV radiation and can be burned by overexposure, as well as the potential development of skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma. These can appear as bumps or lumps on the eyelid, unusually pigmented spots, as well as scabs or sores that don't appear to heal. Any lumps or bumps on your eyelids should be checked by your Optometrist.
TREATMENT: if a cancerous lump is suspected, surgical excision of the lump and the area around it (as well as a biopsy) is the likely course of action.
HOW TO PROTECT YOUR EYES FROM THE SUN
Wear UV400 Sunglasses: UV400 sunglasses protect your eyes from over 99% of the UVA and UVB rays from the sun(2). For added protection, sunglasses that wrap around your head (so no UV enters from the sides or top of the glasses) are the best design.
Wear Wide-Brimmed Hats: this will also prevent the UV rays and sun from hitting your eyes, and ensures more widespread protection than most sunglasses.
Limit Time in the Sun: no sun exposure will ensure no UV rays hit your eyes. Obviously, the sun cannot be avoided altogether, however, limiting time in the sun when the UV is strongest (between 10 am - 3 pm) will result in less UV getting to the eyes.
REFERENCES
Ultraviolet (UV) Radiation and Sun Exposure. (2021). Retrieved 18 August 2021, from Reference here
How can the sun damage your eyes?. (2020). Retrieved 18 August 2021, from Reference here
How the Sun Can Damage Your Eyes | USC Roski Eye Institute. (2021). Retrieved 19 August 2021, from Reference here