Pfizer Inc. stated that it is still working on updating the Viagra's label after the release of several reports on vision loss. Viagra does not increase the risk of blindness, according to a review issued by the company, informs Associated Press.

38 vision loss cases were reported in may by the U.S. Food and Drug Administration, which may have been caused by a condition called Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) after using the erectile dysfunction drug Sildenafil, commonly known as Viagra.

A specialist from the University of Minnesota Medical School, Howard Pomeranz, recalled that "for years, we've known that some men who take Viagra will experience temporary color changes in their vision and see things as blue or green," but " NAION is a much more serious condition because it can lead to permanent vision loss".

"Viagra regulates a chemical in the body to constrict the arteries. This constriction may cut off the blood flow to the optic nerve, especially in people with a low cup to disk ratio, where the blood vessels and nerves are tightly bundled provoking NAION" added Pomeranz.

Still, Pfizer Inc, the Viagra's manufacturer, concluded that it has found no specific evidence of increased risk of blindness among the patients who have been taking Viagra, but the company will include some new information on the drug's label.