THE GOODS : The Discount Years : As we get older, many of the pleasures in life get cheaper. And, thank goodness, so do some of the necessities.

Most people want to be younger.

But if that’s not working, if aches and wrinkles seem to be gaining on you, consider the advantages of getting older.

The number of discounts offered to “mature” audiences has expanded vastly in recent years.

Once, a mere trickle of price reductions were available for people over 65. Today, the trickle has turned into a torrent and benefits people as young as 50, says an author of a book on senior discounts.

Discounts are expanding as more businesses recognize that people over 50 are America’s fastest-growing population segment and control half the discretionary income, says Joan Rattner Heilman, author of “Unbelievably Good Deals & Great Adventures That You Absolutely Can’t Get Unless You’re Over 50” (Contemporary Books, 1994).

Here are a few of the bargains available. Many other places also offer discounts so, if you have reached 50, don’t be shy about asking.

Entertainment & Attractions

Ahmanson at the Doolittle--$41, $45 and $49 theater tickets half price, subject to availability, one hour before all performances. Must have picture ID and pay cash. Minimum age: 65. (213) 972-0700.

Descanso Gardens--$5 admission reduced to $3. Minimum age: 62. (818) 952-4400.

Disneyland--$31 admission reduced to $25. Minimum age: 60. (714) 999-4565.

Hollywood Bowl--Two tickets priced as high as $19.50 may be purchased for $6 each, starting one day before Tuesday, Wednesday or Thursday performances. Subject to availability. Must have Medicare card, driver’s license, RTD bus pass or birth certificate for ID. Minimum age: 63. (213) 850-2000.

Knott’s Berry Farm--$26.95 admission reduced to $17.95. Minimum age: 60. (714) 220-5220.

L.A. County Museum of Art--$6 admission reduced to $4. Minimum age: 62. (213) 857-6000.

Los Angeles Philharmonic concerts at Dorothy Chandler Pavilion at the Music Center--Tickets priced from $9.50 to $50 may be purchased for $6 up to two weeks before Wednesday evening and Friday matinee performances. Subject to availability. Limit one ticket per ID. Minimum age: 62. Seniors also get 50% discounts on some subscriptions. Two per ID. Minimum age: 63. (213) 850-2000.

Los Angeles Zoo--$8 admission reduced to $5. Minimum age: 60. (213) 666-4090.

Magic Mountain--$29 admission reduced to $18. Minimum age: 55. Proof of age required. (805) 255-4111.

Mark Taper Forum--$28-$35 tickets available for half price, subject to availability, on day of performance only. (Saturday nights not included.) Must have Medicare card to prove age and must pay cash. Minimum age: 62. (213) 972-0700.

Museum of Tolerance--$7.50 admission reduced to $5.50. Minimum age: 62. (310) 553-8403.

Richard Nixon Library & Birthplace--$4.95 admission reduced to $2.95. Minimum age: 62. (Everyone free through May 31.) (714) 993-3393.

Universal Studios Hollywood--$29.95 admission reduced to $23.95. Minimum age: 60. (818) 508-9600.

Health Care

Cedars-Sinai Medical Center--Free senior care program offers 10%-30% discount from participating providers of home health care and on orthopedic supplies not covered by Medicare. The program also offers discounts from providers of prescriptions and glasses and offers free health lectures, health insurance counseling, and an information and referral hot line. The fee for an aerobic exercise class is discounted. Minimum age: 65. (310) 855-5454.

Glendale Memorial Hospital and Health Center--10%-20% discounts from participating pharmacies, suppliers of hearing aids, glasses and on some eye exams. Also 5%-20% reduction from participating providers of home health care services. Free screenings for blood pressure and prostate problems, free participation in Walk-a-Diles Walking Club and other exercise classes, and free assistance with Medicare and other insurance problems. Minimum age: 50. Provides $8 mature-driving class, which leads to discounts in auto insurance. Minimum age: 55. (818) 502-2396. ((818) 502-2380 for cancer screenings.)

Lens Crafters--10% discount on glasses, frames and accessories. Will fill out Medicare forms for patients who have had cataract surgery. If a doctor changes a prescription during the six months following cataract surgery, the company will replace the patient’s lenses at no charge. Minimum age: 65.

Santa Monica Hospital--10%-20% discounts through providers of glasses, prescription drugs, hearing aids and home health services. Discounted exercise programs, Medic Alert bracelets and Wednesday evening mammograms. Also free health lectures, walking program, blood pressure screenings twice a month, and eye, ear and skin screenings at different times. Minimum age: 50. Provides $8 mature-driving class, which leads to discounts in car insurance. Minimum age: 55. (310) 319-4560.

Southern California College of Optometry--10% discount on glasses but not on contact lenses. Free cataract and glaucoma screening Monday and Friday mornings. Call for appointment. Minimum age: 62. (714) 449-7400.

YMCA--Membership discounts of $5-$10 a month at most branches. Minimum age: check with branch.

Sports

Hollywood Park--$6 general admission tickets for $4 on Thursdays through July 21. Includes parking and program. Minimum age: 62. (310) 419-1500.

Los Angeles Dodgers--$6 tickets in top deck or outfield pavilion for $3 for all day games, subject to availability. Sales begin 90 minutes before game. Minimum age: 55. (213) 224-1500.

Movies

AMC--50% discount on most tickets. Minimum age: 55.

Edwards--$6.50 and $6.75 tickets are reduced to $3.50 and $3.75. Minimum age: 55.

Mann--$4 tickets for all shows except premieres. Minimum age: 60.

Travel

American Assn. of Retired Persons--for $8 membership fee, offers 5%-10% discounts for three rental car companies and discounts as high as 50% at 22 hotel chains, including Best Western, Holiday Inn and Sheraton Resorts. Also reductions on some tours and cruises. (310) 496-2277.

Amtrak--15% discount on any coach-class ticket. Some exceptions apply. Minimum age: 62.

Gray Line Worldwide--15% off fares for some half- or full-day sightseeing tours at participating Gray Line locations in the United States and Canada. Minimum age: 50 (with AARP membership card).

Airlines

American, Delta, United and some other airlines offer booklets of four coupons for $596 or eight for $1,032. One coupon is required each way on trips within the continental United States and two coupons are needed each way on flights from continental U.S. to Hawaii or Alaska. Reservations must be made 14 days in advance and there may be restrictions. Minimum age: 62.

In addition:

American Airlines--10% discount on any fare, subject to restrictions. Minimum age: 62.

Delta Airlines--10% off published fares to any Delta destination in North America or the Caribbean. Some promotional fares excluded. Some discounts are available for international travel but reductions vary. Minimum age: 62.

Southwest Airlines--10% discount off lowest available fare. Limited seats on every flight. Must make reservations at least one day in advance and present proof of age. Minimum age: 65.

United Airlines--10% discount off any published fare. Must meet advance purchase requirements, if any, on each fare. Minimum age: 62.

Car Rentals

Avis--Discounts to AARP members. Savings vary with location, destination, time of year. Minimum age: 50.

Enterprise--10% discount for AARP members. Minimum age: 50.

Hertz--Discounts for members of AARP, the National Assn. of Retired Federal Employees and retired military officers. Discount and minimum age vary.

Odds & Ends

Backroads--Biking, walking and hiking trips, and cross-country skiing, running and multisport programs. Trips are open to people of all ages, but senior discounts begin at age 60. Each trip has varied daily mileage options and is accompanied by a van, so people of different abilities can take part. Trips are offered in 20 countries and in 20 states. Closest to Los Angeles are five- and six-day biking trips in Big Sur. (800) 462-2848.

First Interstate Bank--Free checking. Minimum age: 55.

Golf Card--Chance to play free twice a year at each of more than 2,500 golf courses, mostly rural ones in the Midwest and Northeast. Must call 24 hours in advance and rent a powered cart. $95 a year for single membership; $145 for double. Minimum age: none, but average age of members is 61. (800) 321-8269.

Hughes Markets--5% discount on almost all items at 51 stores in five Southern California counties. Minimum age: 65.

Quinn’s Health Pantry--two Hollywood health-food stores offer a 5% discount on everything except advertised specials. Minimum age: 55. (213) 663-8307 or (213) 651-5950.

Ross Dress for Less--10% discount on all items every Tuesday at 50 stores in Los Angeles area. Minimum age: 55.

70+ Ski Club--10-page list of free or discounted downhill skiing sites in the United States, Australia, New England, France and Switzerland. Proof of age and $5 fee required. Minimum age: 70. Write for information: 104 Eastside Drive, Ballston Lake, N.Y. 12019.

UCLA Extension--50% fee reduction for many classes. To assure a place, students should pre-enroll in person or by mail. Must present proof of age. Courses are taught primarily on UCLA campus, Downtown at World Trade Center and at Universal CityWalk. Minimum age: 65. (310) 206-6201.