NEW YORK -- After admitting himself to a hospital with symptoms of a severe headache, Gov. David Paterson was diagnosed Tuesday with acute glaucoma in his left eye and was undergoing a routine procedure to relieve pressure on that eye, his office said.

The operation, called an iridotomy, will not have any long-term impact on the governor's overall health, the statement said.

"The governor will remain conscious throughout the procedure, but in an abundance of caution, the Senate majority leader and the Assembly speaker were advised of this pursuant to standard protocol," it said.

Paterson, who is legally blind, went to The Mount Sinai Medical Center earlier Tuesday after experiencing what his office called "migraine-like symptoms" in the middle of the night.

Paterson lost sight in his left eye and much of the sight in his right eye after an infection as an infant. He can see shapes and usually recognizes people as they approach.

He can read for just a few minutes at a time, with the text held close to his face; usually his aides read to him. At a bill signing last week, Paterson put his nose to the bill to find the right lines on which to sign.

Paterson's health has been a concern in recent years, with at least two other hospitalizations, although he is known for his basketball skills and also ran the New York City Marathon.

In April 2006, when he was state Senate minority leader, Paterson was admitted to a hospital with chest pain and underwent a CT scan, cardiovascular stress test and echocardiogram. The tests came back normal and he was released after about 12 hours.

At the time, a Paterson spokesman said he had no history of heart trouble.

Last July, Paterson fainted on an airplane on his way to Buffalo. He was briefly hospitalized and the following day had an angiogram, which was normal. Doctors said they found no evidence of heart disease.

Paterson, who turned 54 Tuesday, was sworn in as governor on March 17, days after former Democratic Gov. Eliot Spitzer resigned amid a prostitution scandal. He had served as Spitzer's lieutenant governor for 14 months.

When he succeeded Spitzer, New York was left without a second-in-command; voters won't pick a new lieutenant governor until the next gubernatorial election in 2010.

Senate Majority Leader Joseph Bruno, a Republican, is next in line of succession and would be acting governor if Paterson were out of state, or became incapacitated or died.

Bruno said he learned the governor was in the hospital around 6 a.m. Tuesday.

He noted that Paterson had recently put him in charge of the executive branch when the governor was in Washington for meetings, and greeted him on the phone with, "Hi, governor." The two men are friends.

Paterson, who lives in the governor's mansion but has an apartment in Harlem, was in New York to speak at Tuesday's commencement at Columbia University, where he earned a bachelor's degree. He was to receive a medal of excellence but his office canceled the appearance. His wife, Michelle, came to Mount Sinai several hours after he checked in.

The glaucoma procedure caps two tumultuous months in office.

A day after being sworn in, Paterson revealed that both he and his wife had had affairs during their marriage but had resolved to work out their problems.

He became the state's chief executive just two weeks before the budget was due. Facing a looming $5 billion deficit, he immediately called for hundreds of millions of dollars in spending cuts, some of which he persuaded the Legislature to adopt.

Since then he has replaced several Spitzer appointees; ordered a 3.5 percent cut in spending by state agencies; taken on powerful labor unions by opposing their efforts to sweeten pensions; and gotten the state attorney general to investigate claims by some lawmakers that the state police operated a rogue unit.