Almost everyone knows that older Americans, particularly after retirement, find it increasingly difficult to maintain their standard of living. Not everyone, however, knows that discounts are available to older persons for a variety of purchases ranging from daily necessities to theater tickets.

Discounts are offered to older Americans throughout the Washington metropolitan area. The Montgomery County Division on Aging publishes a discount Program Directory that lists more than 300 retail outlets that offer discounts ranging from 10 per cent to 50 per cent. The directory also lists discounts available on products and services from adult education to wigs, and including quto repairs, drug prescriptions, clothing, hair styling, hearing aids, restaurant meals and television sales and service. Directories and identification cards are available through the Division office (telephone 279-1487) to residents 65 years of age and older.

Here are sample listings: "Free checking account - no monthly service charge, no minimum balance, no charge per check, prepaid bank-by-mail envelopes", "$75 discount on any hearing aid, 25 oer cent discount on batteries and accesories"; "free courses in reading; writing and conversational English to nonreaders and the foreign born. All materials, books etc., are free."

Some of the directory entries are national organizations like motel chains or rent-a-car firms. some are statewide, such as the Maryland Department of Natural Resources, which offers free services and fishing and hunting licenses at reduced costs. The Kennedy Center offers two-for-one theater tickets for many performances.

For all elderly people in the Washington Metropolitan area there are substantial discounts for Metro bus transportation and for the new Metro rail system. Until recently discounts on buses were offered only during non-rush hours, now the half-fare charge applies at any hour. Users of this service are required to have a Senior Citizens Fare Identification Card, obtainable at any public library as well as at Metro offices. The new subway system also offers fares at one half the regular ruch-hour charge. Special fare cards must be used and these are available for purchase over the counter at Metro sales outlets or Metrobus division offices. For the location nearest you call Consumer Assistance, 637-1328, or Senior Citizen information, 637-1179.

Similar listing are provided by Prince George's County, which publishes the "Prince George's Senior Citizen." The listing and identification cards for residents over 60 are available through the Department of Services and Programs for the Aging, telephone 350-0650.

Arlington County in Virginia distributes its lists and identification cards through its public library system. Information is also available by calling 558-2015. Fairfax County distributes information through its recreation center or by mail. The number to call is 691-2185.

The District of Columbia's ofice on Aging has compiled a guide containing more than 200 listings of businesses where senior discounts are given. Sarah McCarthy, who is coordinating the program, expects directories to be available in late August. Latest information can be obtained by calling the information and referral section of the office, 724-5626.

It is not uncommon for unlisted stores to offer discounts to the elderly. The Prince George's directory states. There may be other businesses besides these willing to offer discounts to Senior Citizens. Ask them - and then tell us."

Govermental agencies do not specifically endorse the businesses listed. The directories are published only as a service to the elderlyl card holders.

A casual survey of users or potential users of the discount services indicates that a number of older persons are totally unaware of these opportunities or have only limited knowledge about them. Among those who use the discount card there is mixed reaction. Some are conviced that the program means real savings for them and that it also enriches their lives when, for example, they attend theater performances and other events at reduced prices.

Other users feel that the program brings only limited benefit because shops offering discounts are too far from their homes, or because many important products or services like food, gasoline or utilities are generally not included.