It may be days before Governor Paterson returns to work, as he recovers from an attack of an unusual form of glaucoma that struck him in the middle of the night with a burst of excruciating pain.

With his wife by his side, Mr. Paterson, who turned 54 yesterday, was rushed out of his Harlem apartment to the hospital yesterday before dawn after he was stricken with what he thought was a severe migraine.

Doctors quickly discovered that Mr. Paterson, who is blind in his left eye and has impaired vision in his right, suffered from acute angle-closure glaucoma in his left eye. Doctors said the glaucoma was not related to the governor’s blindness.

Hours later, doctors numbed his eye and used a laser beam to cut a tiny incision in his iris to drain excess fluid and relieve the extreme pressure that had built up within his eyeball. The procedure, called an iridotomy, lasted about five minutes and did not require sedation.

In the next few days, Mr. Paterson will undergo the same procedure in his right eye as a precautionary measure.

The governor’s emergency medical condition caused a brief scare in a political world already on edge from the recent resignation of Governor Spitzer.

Legislative leaders received early-morning calls from the governor’s staff alerting them that he had been brought to the hospital.

Doctors said Mr. Paterson’s condition was not life threatening and deemed the governor, who has had two other emergency trips to the hospital in the last two years, in good health. Mr. Paterson returned home yesterday afternoon and was said to be resting comfortably.

He has no public schedule today, and his staff yesterday canceled events slated for tomorrow and Friday. A spokeswoman for the governor said last night that it was uncertain if the governor would resume his normal duties this week.

At about 3 a.m., Mr. Paterson felt “migraine-like symptoms” and asked the state police to drive him to a hospital.

He was admitted into Mount Sinai Medical Center on the Upper East Side just before 4 a.m. and was evaluated by a neurologist and then referred to a neuro-ophthalmologist, who diagnosed him with glaucoma.

Dr. John Danias, an ophthalmologist who treated Mr. Paterson, said the governor suffered from ocular pressure “way above the normal range.” He was treated with topical medication, pills, and an intravenous hook-up.

Dr. Danias, speaking to The New York Sun, said the governor was lucid and awake while he was receiving treatment and was “participating in the decision process.”

The doctor said Mr. Paterson “was tired from going through this experience, for having so much pain for so long a period.” In a news conference at the medical center, Dr. Danias said the governor had a “hard night.”

Mr. Paterson began to feel better at around 11 a.m. and underwent the laser procedure around 2 p.m.

At 6:30 a.m., aides to the governor contacted the Republican Senate majority leader, Joseph Bruno, and the Democratic speaker of the Assembly, Sheldon Silver, and advised them of the governor’s condition.

“They didn’t have to, but it was nice that they did,” a spokesman for Mr. Bruno, John McArdle, said.

Mr. Bruno, 79, would serve as acting governor if Mr. Paterson died or resigned from office until the general election in November. If Mr. Paterson became incapacitated within three months of Election Day, November 4, Mr. Bruno would serve until the next general election the following year.

Mr. Silver, 64, follows Mr. Bruno in the line of succession, but he would serve until the Senate selects a new majority leader, who would assume the position of acting governor until the next election.

Mr. Paterson was supposed to have delivered a commencement speech at Columbia University, his alma mater, yesterday. Mr. Paterson asked that Attorney General Cuomo, a Democrat who is a possible candidate for governor in 2010, give a speech in his absence.

In the past two years, Mr. Paterson has had unrelated health scares. Last July, he was on a commercial flight when he began to feel dizzy and fainted briefly. Doctors said he was healthy but advised not to sleep with his shirt collar buttoned.

In April 2006, Mr. Paterson was hospitalized in Albany overnight after suffering chest pains. Doctors performed a CT scan and other tests, which came back normal.

Last year, Mr. Paterson experienced problems with his teeth and saw a dentist several times.

Mr. Paterson, a former state senator, was Mr. Spitzer’s lieutenant governor and took office two months ago after Mr. Spitzer resigned amid a prostitution scandal. He is serving out Mr. Spitzer’s four-year term, which ends on December 31, 2010, and has indicated that he intends to seek another term.

Mr. Paterson is the state’s first African-American governor and the nation’s second legally blind governor.