Sunlight is an important source of vitamin D, but excessive exposure can also have a harmful effect on the human body. The effects of sunburn on the skin are well-documented, but the UV rays can also damage the delicate eye area.

A sensitivity to light can be a trigger for migraine headaches. To combat this problem, you can try wearing tinted lenses to lessen the effect of the UV rays hitting your face. Dark sunglasses can be helpful for wearing outdoors to protect your eyes from the direct effects of the sunlight, while lighter tinted lenses can be useful for indoors. You can also ask your optometrist about photochromic lenses, which are designed to change the level of tint according to the intensity of light. This can save you the hassle of having to swap out a particular pair of tinted lenses for another as you move throughout the day.

Macular degeneration is an age-related condition that causes a gradual loss of the central vision in your eyes. Unfortunately, it can also be exacerbated by exposure to UV rays. The ultraviolet radiation can damage cells in the retina, the light-sensitive layer at the back of the eye.If you have macular degeneration, it's essential to wear sunglasses to protect your eyes while outside. Certain types of coloured lenses (such as yellow, orange and brown) can help improve your contrast vision. Always look for lenses that that offer 100 per cent UV protection and are polarised to protect against the glare of reflected sunlight. I

f you're looking to trial contact lenses, you will still need to wear sunglasses and a hat to protect your eyes from the UV rays. There are many different types of contact lenses you can try, including Acuvue Moist, Proclear 1 and other brands.You'll need to test out the brand and fit that feel the most comfortable for you. Water content isn't the ultimate indicator of comfort as some of the most oxygen permeable lenses today still have a low water content. Ask your optometrist about doing a trial between different pairs.

Uveitis is a condition where the middle layer of the eye (the uvea or uveal tract) becomes inflamed. It's usually treated with steroid medication, which help to disrupt the immune system and stop the release of chemicals causing the inflammation. It can be injected, taken orally or applied in eye drops.Sometime an immuno-suppressant medication may be prescribed instead. In rare cases, surgery is required to treat severe or recurring uveitis. Anterior uveitis is a common form of uveitis that involves inflammation in the front part of the eye - this can affect the iris or coloured section of your eye. When being treated for this condition, your vision can become blurred as a result of the medication. This may cause headaches.If you are undergoing radiotherapy, your medical specialist should provide adequate eye protection.

PUVA treatment is a combination of psoralen (chemicals found in plants) and ultraviolet A. It was originally developed to treat psoriasis and is also prescribed to treat other skin conditions. Again, eye protection should be provided during the treatment but you can get a UV-absorbing dye placed onto your existing lenses (if they haven't already got an added coating).