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

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