Re: What caused Galileo to become blind?

Galileo discovered sunspots by looking at the sun through his
telescope. Unable to leave well enough alone, he continued to
look at the sun through his telescope, until he finally went
blind.

This, at least, is the most plausible explanation; I suppose
there might have been some of it in his family. He was around
55 or 60 when he went blind.

                              Dan Berger

                              MadSci Administrator

Admin note:

We received the following additional answer:  


Galileo's blindness was certainly NOT due to his solar observations, which
he made in 1613.  A quarter of a century later, he became blind from
cataracts and glaucoma, at the age of 72 (NOT "55 or 60").


This matter was well discussed by a professor of ophthalmology

-- see http://mintaka.sdsu.edu/GF/reading.html#Mulder

for the reference.  Galileo's solar observations were made
near sunset, when it is quite safe to look at the Sun, even
through optical instruments.