New York City ? Gov. David Paterson has been diagnosed with acute glaucoma in his left eye and was undergoing an outpatient laser procedure Tuesday, his office said.

The governor, who is blind in his left eye and has only limited vision in his right, received the diagnosis after admitting himself to a hospital with symptoms of a severe headache. He was undergoing an iridotomy, an operation that will not have any long-term impact on the governor’s overall health, a statement from his office said.

Dr. Gregory Harmon, a Manhattan opththalmologist and chairman of the Glaucoma Foundation, said it sounds like the governor probably suffered an an attack of acute angle closure glaucoma, which is an emergency situation that occurs when fluids that normally drain freely from the eye suddenly become completely blocked.

The condition leads to an immediate buildup in pressure within the eye. It is incredibly painful, and causes not only headaches but, in some cases, vomiting due to the severity of the agony.