A man, whose identity could not be revealed, was forced to seek medical help after temporarily losing his sight every time he had sex.

As per the NCBI ROFL blog, the patient would go blind immediately after the ejaculation but the blindness would never occur while performing any other strenuous exercise.

The report revealed the cause of the condition to be vasoconstriction, where the muscle walls contract around a blood vessel, restricting the flow of blood.

Vasoconstriction is the same condition that causes erectile dysfunction.

Doctors had earlier speculated that an embolism was causing the man's blindness.

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

The original report was published by the Department of Ophthalmology at Glostrup Hospital, University of Copenhagen.