White flashes

This only happens at the end of the day when it does, but when reading sometimes, I see a brief small round flash of light above and maybe a little to the side of the line I am reading. It just lasts for a second and is small (seems like a few mm) compared to my entire field of vision. It will do it a few times and then go away. Any thoughts on what this could be.

[Flavius G Pernoud III, MD]

You need a dilated eye exam. You might have a posterior vitreous detachment. The gel that fills the back part of the eye shrinks with age and eventually pulls away from the retina. This frequently causes light flashes. This shrinkage may cause a retinal tear and subsequent retinal detachment.