High doses of sildenafil cause men to see blue

When taken in high doses, first-time users have rare visual side effects such as colour blindness
Australian Associated Press

It (most likely) won’t send patients blind but taking sildenafil could cause some people to develop ongoing sight problems, including bright blue vision.

A study of patients in Dunyagoz Adana Hospital, Turkey, found male patients who had taken a high dose of sildenafil experienced myriad side effects, including abnormally dilated pupils, blurred vision and light sensitivity.

In serious cases, vision was tinted a bright blue paired with red-green colour blindness.

Author Dr Cuneyt Karaarslan said that for the vast majority of men, any side effects would be temporary and mild.