# Alhazen's problem history

I was wondering if anyone has read '' alhazen book of optics'' and has understood his solution of Alhazen's problem.

I know a modern solution of the problem by Dörrie-100 great problems of mathematics, but I'm interested really in ibn alhaytham's solution. I'm just curious about how he went about solving the problem without the modern tools. Also I couldn't find the problem in his book, maybe I didn't look carefully for it, but it would be nice if someone could reference me to it in his book also.