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"Scientists don't have a good bead on the prevalence of eye damage after a solar eclipse. In one study, conducted in 1999 after a solar eclipse visible in Europe, 45 patients with possible solar retinopathy showed up at an eye clinic in Leicester in the United Kingdom after viewing the eclipse. Forty were confirmed to have some sort of damage or symptoms; five of those had visible changes in their retina. Twenty of the patients reported eye pain, while another 20 reported problems with vision. Of the latter group, 12 reported that their sight had returned to normal seven months later, but four could still see the ghosts of the damage in their visual field, such as a crescent-shaped spot visible in dim light.

"Our series demonstrates that, contrary to popular belief, the majority of people with eclipse retinopathy are not totally blinded," the researchers wrote in 2001 in the journal The Lancet. However, they warned, earlier post-eclipse studies had turned up more severe problems in patients, suggesting that widespread media warnings not to look at the eclipsing sun may have prevented more damage during recent eclipses.

Research also suggests that while a lot of the damage may heal, some may be permanent. One 1995 study followed 58 patients who sustained eye damage after viewing a 1976 eclipse in Turkey. Healing occurred during the first month after the eclipse, the researchers reported in the journal Graefe's Archive for Clinical and Experimental Ophthalmology, but by 18 months, whatever damage still remained was permanent up to 15 years later."