Photophobia is a sensitivity to light. You may experience a sensitivity to very bright light, such as sunlight, or low light, such as incandescent lighting. Depending on the severity of your sensitivity, you can have a little discomfort or a very painful eye.
Those with light coloured eyes (e.g. light blue) are more likely to be affected by Light Sensitivity, but Photophobia is also caused by a range of other eye conditions such as Uveitis.
The course of treatment will very much depend on the underlying cause. If the condition causing the problem (e.g. cataracts or uveitis) is treated, you should see an improvement in your light sensitivity. If you are someone whose eyes are naturally light sensitive, an optometrist can advise on tinted glasses to help reduce the discomfort or pain.