For one man, love was literally making him blind. Well, at least having sex was.

The unnamed patient had to seek medical help after going temporarily blind every time he climaxed during sex, the Daily Mail reported.

The NCBI ROFL blog, which is written by two PhD students at UC Berkeley, uncovered the story from the PubMed database.

In the original report, published by the Department of Ophthalmology at Glostrup Hospital and the University of Copenhagen in Denmark, experts found the “mysterious” condition was being caused by vasoconstriction, which is the narrowing of blood vessels by muscles in their walls. When this happens, blood vessels constrict and the flow of blood is restricted or slowed, according to the National Institutes of Health.

Vasoconstriction can also be a contributing factor in men who suffer from erectile dysfunction.

“Hypothetical mechanisms of transient monocular visual loss in our patient include vasoconstriction or embolism in the arterial blood supply of the eye,” the report stated. “The repeated and completely transient nature of our patient's symptoms supports the fact that embolism was not involved.”

Doctors eventually treated the patient using drugs to widen his blood vessels. 

Click here to read more from the Daily Mail.