It is a self-contained, flying hospital for the human eye that can provide some of the world's most advanced ophthalmological surgery within three hours of touching down at a foreign airport.

Orbis, a DC8 jetliner converted into a hospital, parked at National Airport yesterday. It is preparing for its second international tour in June, with a goal of educating foreign surgeons and generating good will for the United States overseas.

Yesterday morning, about 100 federal officials, foreign diplomats and corporate executives gathered in a hangar at National Airport to hear pleas for money for Project Orbis, the nonprofit corporation that operates the jet. They also went to see the aircraft's equipment and to visit with its medical staff.

Later in the day, Barbara Bush, wife of the vice president, toured the jet in the company of about 30 second-graders from Washington's Horace Mann Elementary School, who have been studying blindness.

The jet has laser equipment in the examination area, an operating room that can handle complex microsurgery, a classroom for up to 18 doctors from the host country, a medical library and a recovery area.

Founded by Houston ophthalmologist David Paton, Project Orbis needs $3 million a year to operate.

Most of the money comes from individuals, foundations and corporations. United Airlines donated the DC8.

The U.S. Agency for International Development has given the program about $2.3 million since 1979, accounting for 20 to 25 percent of its needs. At yesterday's program, AID deputy administrator Jay Morris announced a new grant of $200,000.

Project Orbis estimates that blindness afflicts 42 million people worldwide and that another 500 million have diseases or conditions that contribute to it.

"Blindness is simply not necessary for the great majority of people who suffer from it," said ophthalmologist Robert Munsch, who coordinated the jet's first world tour. It visited 20 countries on that trip, including West Germany, China, Morocco, Turkey, Jordan and Sri Lanka.

Orbis surgeons, many of them American doctors who volunteer their services for a week or more, operated on about 800 patients during the first tour.

Their main goal was to teach local surgeons, who watched the operations on color television screens in the Orbis classroom. About 1,200 doctors attended the surgery classes during the first tour. In the two weeks that the plane normally spends at one site, Orbis officials said local surgeons can gain valuable new skills.

"In many countries, we've actually seen doctors later doing operations they couldn't do when we arrived," said external affairs director Oliver Foot.