You'll go blind doing that!

These anti-impotence drugs just faced this strike on possible vision loss. Pfizer claims no sign of this risk previously; however it has long been known that many people have "blue" vision. The blue vision is due to the blockage of an enzyme in the retina, and usually only occurs in men taking more than the recommended dose.

So your mom may have been wrong about "going blind," unless of course you're on viagra.