The Supreme Court agreed yesterday to decide whether a state can prohibit optometrists from practicing under the Trade or corporate names commonly used by large commercial operations that hire professionals to examine eyes and fit and prescribe lenses.

The justice will review a ruling in a Texas case by the 5th U.S. Circuit Court of Appeals that a trade name is "encompassed within the meaning of advertising" and therefore is commercial speech of the kind protected by the First Amendment to the Constitution.

In addition to Texas, about 20 states restrict or prohibit optometrists from practising under any name but their own.

The appeals court rejected as "unpersuasive" arguments by the Texas state affiliate of the American Optometric Association (AOA) that a ban on trade names preserves high-quality eye care and therefore out-weighs the loss of free speech involved. Advocates of trade names claimed that those using them in Texas provide services of equal quality for sharply lower fees.

The court took other action:

State vs. Federal Utility Regulation.

In a case from Rhode Island, the court let stand a ruling that sharply restricts the power of the state - and, by implication, possibly of other states - to regulate electric rates to assure that they are reasonable.

The case began in late 1975 when the Narragansett Electric Co. asked the Rhode Island Public Utility Commission (PUC) to raise prices to its retail customers sufficient to compensate for a $9.3 million increase in wholesale prices.

Narragansett buys all of its electricity from the New England Power Co. Both the utility and NEPCO are owned by the New England Electric System, a holding company. NEPCO is one of several interstate wholesalers regulated by the Federal Energy Regulatory Commission.

The PUC claimed, and the utility denied, that it had the right to investigate the reasonableness of the $9.3 million added cost - and it concluded that $3.9 million of it should be disallowed.

Narragansett contended that the PUC had no such right, the reasonableness of the $9.3 million having been determined by the federal agency.

The Rhode Island Supreme Court agreed with the utility that the PUC must treat the price paid to NEPCO as "a reasonable operating expense."

The state said the decision, even though binding only in Rhode Island, may have "major national significance." Airline Liability

Four years ago, Manufacturers Hanover Trust Co. of New York City notified Alitalia, the Italian ariline, that it was going to send $20,00 in bank-notes to a bank in Libya.

At kennedy International Airport, Alitalia took special precautions to conceal the shipment and protect against possible theft or robbery.

Nonetheless, on Jan. 4, 1074, three armed, masked men - still at large - came to Alitalia's cargo warehouse at Kennedy, herded employes into wash-rooms and made off with the $200,000.

Was Alitalia liable? No, it said: it had taken reasonable security measures. Yes, said the 2d U.S. Circuit Court of Appeals.

The Supreme Court let the decision stand.