The Federal Trade Commission yesterday unanimously approved new rules permitting advertising of prices and other information about eyeglasses, contact lenses and eye examinations.

The new rules will essentially preempt part of the laws of 40 states, including Virginia, which now prohibits or restrict eyewear and examination information.

In addition, the new rules will eliminate the restrictions imposed by private professional associations, even in those states with laws permitting advertising. Advertising bans contained in ethical codes in the District of Columbia and Maryland will be illegal under the new rules.

Another major provision requires that consumers be provided with copies of their prescriptions after they have had their eyes examined.

The rules will become effective 30 days after publication in the Federal Register unless stayed by a court during the appeals process.The American Optometric Association announced immedeately after the FTC vote that it would file an appeal. It said that parts of the new rules are "not in the best interests of consumers."

For their part, FTC members predicted that the rules would be a boon to the 112 million Americans who wear corrective lenses and spend an estimated $4 billion a year on glasses, lenses and eye exams.

"By permitting consumers to receive price and other information . . . and by guaranteeing their right to their own prescription, this rule will greatly facilitate comparison shopping for the best price and quality and should, in addition, promote competition among members of the industry," commission member Elizabeth Hanford Dole said.

The "eyeglass" rule, first proposed in December 1975, marks the culmination of the first formal rulemaking proceeding under new authority granted the FTC by Congress in 1975.

The FTC said yesterday the hearing record indicated that consumers were spending substantially more for eyewear than they would if they had adequate information about prices and availability. FTC Chairman Michael Pertschuk noted that prices for the same pair of glasses may vary as much as 300 percent within the same city and that consumers armed with more information will have an opportunity to pay lower prices.

The agency also found that prices for eyewear were generally 25 percent higher in states with advertising bans than in those that permitted some advertising.

The agency said the restrictions had an especially adverse impact on the aged, who more often need corrective lenses than the general population. The FTC also found that the number of people getting eyeglasses was 17 to 35 percent greater in states permitting some advertising than in states where all advertising is banned.

The new rules will affect more than 40,000 ophthalmologists, optometrists and optician. Ophthalmologists are medical doctors who can examine eyes, prescribe and dispense lenses and also perform such medical services as surgery.OPtometrists, who are not medical doctors, can measure for and dispense corrective lenses. They are also trained in detecting eye diseases but cannot treat them. Opticians are not doctors and cannot examine the eyes or prescribe for glasses but are qualified to sell eyeglasses prescribed by ophthalmologists and optometrists.

As of June 1, 1977, the FTC said, ophthalmologist and optometrists were prohibited from advertising at all in 19 states. In 17 other states, opticians are permitted to advertise the price of eyeglasses and lenses but optometrists were not. In nine states, there was some form of restriction on advertising for optometrists and opticians. More than 40 states prohibited optometrists from advertising their examination fees.

Only six states permitted unrestricted price advertising by optometrists and opticians, but the ethical codes of private associations in those states "filled the gap" by restricting advertising in some way, FTC lawyers say.

The new rules will not preempt state laws restricting advertising if the restrictions apply to all consumer goods across the board. In addition, the rule also permits states to require advertisers to explain what is included in the advertised price.