<unk> s (also known as age spot, solar lentigo, "lentigo senilis", "old age spot", "senile freckle") are blemishes on the skin associated with aging and exposure to ultraviolet radiation from the sun. They range in color from light brown to red or black and are located in areas most often exposed to the sun, particularly the hands, face, shoulders, arms and forehead, and the scalp if bald. The spots derive their name from the fact that they were once incorrectly believed to be caused by<unk>  problems, but they are physiologically unrelated to the<unk> , save for a similar color. From the age of 40, the skin is less able to regenerate from sun exposure, and<unk> s are very common in this age group, particularly in those who spend time in the sun. In the overwhelming majority of cases,<unk> s pose no threat and require no treatment, though they occasionally have been known to obscure the detection of skin cancer. However, despite being a benign condition,<unk> s are sometimes considered unsightly and some people choose to have them removed. This can be done by electrosurgery, laser treatment, cryotherapy, or the use of depigmentation agents, such as hydroquinone, tretinoin, topical cysteamine, azelaic acid, or alpha hydroxy acids.
Liver spot
Roth's spot
Forchheimer spots
Biliary sludge
Bitot's spots
Bier spots
Blind spot 
Elschnig spots