A man suddenly went blind in one eye after taking Viagra.
Viagra made a man go blind in one eye
The 32-year-old from Iran took a large dose of sildenafil - the main ingredient in the erectile dysfunction pill - and lost the sight in his right eye almost straight afterwards.
Despite the best efforts of medics, the damage was too extensive and he lost all vision in the eye and doctors say it is the clearest evidence yet that taking Viagra harms the eyes.
Sildenafil increases blood flow to the penis by relaxing the blood vessels but it is suspected that it has an adverse impact on other sensitive vessels in the body - including those in the eyes.
The team at Farabi Eye Hospital in Tehran said: "Several serious retinal vascular accidents have been reported following sildenafil use but the exact role of this medication is not clear.
"Since the patient was otherwise healthy without known risk factors for vascular disease... and in addition the close temporal relation between sildenafil intake and incidence of the disease, we speculated that the drug could play a causal role in this clinical scenario."