A panel of seven Navy officers began deliberating yesterday in the court-martial of Cmdr. Reginald E. Newman, charged with lying about his role in recruiting Cmdr. Donal M. Billig to the Navy. The court-martial board adjourned for the night after deliberating 2 1/2 hours.

In a separate court-martial, doctors testifed about the limitations they found when testing the eyesight of Billig, who is charged with involuntary manslaughter in the deaths of five patients.

In closing arguments at the Newman trial, prosecutor Lt. Elizabeth Dean said Newman, in recruiting Billig in 1982, "placed a bet on a horse that had a problem and didn't finish the race." Since then, she said, Newman has tried "to go back and erase" his actions.

The Navy has accused Newman of falsely telling investigators that adverse information about Billig's professional experience had been shown to a panel that ruled on whether to commission the doctor. Newman also is accused of lying about whether he told a subordinate, Lt. Cmdr. Jerry D. Penn, to change a form that pointed to Billig's professional troubles at a New Jersey hospital.

Defense attorney Lt. Cmdr. Irving Warden described Newman as a "conscientious naval officer" who had "unknowingly misled" investigators based on information from Penn, who is also charged with lying about the Billig recruitment.

"There's a lot of reason to believe the accused and a lack of substantive evidence to disbelieve him," Warden said.

Billig's ability to see and to operate was scrutinized for hours yesterday at his trial.

Medical documents submitted as evidence yesterday showed Billig had suffered an injury to his right eye after a tennis ball hit him in 1978 and left him with 20/400 vision.

Two ophthalmologists and a family practitioner testified that signs of scarring were found or reported to them by Billig during their examinations. Dr. William Ryckman said, "I was quite concerned that without depth perception he couldn't accomplish fine, delicate work."

Ryckman's exam, completed as part of an application to the Air Force, recommended that Billig receive a more intensive exam. A month later, Billig applied to the Navy.

Defense attorneys established yesterday that according to Navy medical regulations, good vision in one eye is all that is necessary to be inducted for service.

Lt. Cmdr. George Miller, the Navy doctor who tested Billig for his commission in 1982, however, testified that he did not realize Billig was applying for admission to the Navy or that he wanted to be a cardiothoracic surgeon.

Asked if he would have found Billig capable to operate without depth perception, Miller said: "I think it would have been inappropriate for a cardiothoracic surgeon to have this defect."