Ultraviolet (UV) radiation is undetectable by the human eye, although, when it falls on certain materials, it may cause them to fluoresce—i.e., emit electromagnetic radiation of lower energy, such as visible light. Many insects, however, are able to see ultraviolet radiation. ^{[source: Britannica]}

The eyes are very sensitive to UV radiation. This is due to the fact that cornea absorbs high doses of UV light. This may cause a temporary clouding of the cornea--a condition known as snow-blindness. Chronic effects of exposure to UV radiation include corneal damage, cataracts, and macular degeneration. These conditions may ultimately lead to blindness. Melanoma (form of skin cancer) can also develop in the human eye. ^{[source: Sciencing]}