Ellen Hitsman felt pretty spry in 1976 when, at age 69, she painted her own house. But since than, a swelling in her legs and a left wrist which broke when she stumbled on her own front step over a year ago have sabotaged her self-reliance.

Her wrist is still stiff. She said she doesn't trust it to hold anything. When the house needs repainting, someone else may have to do it.

"An unsteady as I am now, I would be afraid to get up on a ladder," she said.

Ellen Hitsman sat in a Detroit senior center. At an adjacent sofa, Charles Lucas, 76, said he had more trouble hearing than he used to. George Bouris, 67, lifted a magnifying glass to the page he wanted to read.

Age brings infirmities; everyone knows that. But few buildings, machines or other devices are designed for use by the elderly. Weakening ears, eyes, and sense of touch meet an environment that often confounds the aged.

Mere bumbling, stumbling or embarrassment may result. For example an aged person may fail to see a child's toy on the floor, thanks to glare that blinds clouded eyes.

But other consequences can be more serious. Imagine an old man who doesn't recognize the yield sign on the highway; it's just a yellow blur. Or a woman in a wheelchair washing a sweater in a sink and not realizing the hot-water pipe is seriously burning her knee.

Particularly frightening, and sometimes deadly, can be a kitchen grease fire. The crackling of it may not be loud enough for feeble ears to hear. The smell may not alert a weak nose until too late.

Delicate cups and saucers are hardly tailored for arthritic hands. Tiny numbers often are illegible on thermostat controls. This list goes on.

In times when older people made up a tiny segment of the population, perhaps such problems were easier to ignore. But the population age 65 and over increased 18 percent from 1970 to 1977. We have 22 million Americans 65 and over today, and we may have 30 million in 2000 A.D.

A small but growing number of architects, product designers and social scientists are trying to recognize what is different about older people and what can be done to improve life for them.

Examine a human body as it enters its late 70s.

The eyes are affected by gradual lens stiffening and clouding. Light tends to glare for the elderly, colors to fade (blues the most and red the least), depth perception to diminish and details to disappear.

The middle ear gets more rigid, which often makes hearing more difficult in crowded places or anywhere with background noises. High-pitched and whispered sounds are often inaudible. The sources of noises are harder to determine, and some combinations of carpeting, draperies and acoustical tiles can make hearing almost impossible.

The sense of smell dulls. Food tastes blander. Some of the aged even lose interest in eating.

The sense of touch diminishes, as does fine muscle control. Turning pages and fishing for change can become difficult tasks.

Few people over the age of 70 have not been affected by at least some such changes. But the rate and degree can vary widely.

So says Dr. Leon A. Pastalan, of the University of Michigan's Institute of Gerontology, who has spent more than a decade studying the special needs of the elderly.

His most famous work involves his development of an "empathic model" -- a set of glasses, ear plugs and a local anesthetic to help young people acquire the sight, hearing and sense of touch of persons in their 80s.

The model, developed with experts in optometry, and audiology, has been used by Pastalan and cohorts to help determine environmental inadequaces for the elderly.

Architecture and psychology students at the university have worn the gear in field work, but sadly for Pastalan, manufacturers of appliances have show scant interests in using the equipment in product research.

Most recently, he finished a study in which elderly people were tested for their preferences in lighting, temperature and ambient noise in a specially constructed room.

The room resembled a den in which participants watched television, read, and performed other ordinary tasks. Elderly participants' responses to light, noise and temperature changes were compared to those of younger people.

Pastalan found older people were more disturbed by human sounds than traffic sound. Background noises seemed generally to bother elderly subjects more than younger ones.

In lighting experiments, what was comfortable for those in their 60s was termed too dim by participants in their 70s.

Temperature-preference differences, however, weren't considered significant.

Despite folk wisdom that old folks like to feel toasty, Pastalan found no significant differences in younger subjects.

Questionnaires distributed to participants, however, disclosed some temperature-control idiosyncrasies of the aged. Elderly subjects tended to heat their living rooms by day -- a sign of gregariousness -- but not their bedrooms and bathrooms at night.

Pastalan says the later finding deserves further study: if an old person collapsed in an unheated bathroom in winter, disaster could result.

Other researchers are studying problems that relate more to changes in body shape, size and tone.

Dr. Joseph Konchelik, an Ohio State University industrial designer, has sought solutions to problems posed by furnishings for older people.

As people age, they can lose about four inches in height and have more pronounced shoulder roll, and their knees may not bend very well.

Older people with weakened leg muscles tend to drop, rather than ease, into chairs.

And, as if to add injury to insult, the aging process tends to rob the buttocks of padding, making such shocks harder to absorb.

At a Seattle conference of interior designers Konchelik and Louis Tregre, and architect and interior designer from New York City, presented general guidelines to help solve elderly furnishing problems:

Chairs should have arms for the person to push against when getting out. Seats should be 15 inches high at the front, 12 inches at the back, with firm, thick padding. The contour of backrests should reflect use by people with rounded shoulders and shorter torsos.

Beds might have fenders to prevent the person from falling out, but also to provide less harsh protection than metal support posts which, along with crank handles, caused 60 percent of injuries in one health-care center. Konchelik said crank handles should be removable.

Bathrooms should have handrails flanking toilets, floor-to-ceiling mirrors and hidden or insulated hot water pipes.

Tables too often are obstructions to the elderly, especially coffee tables. They make it harder for old people to make their way in and out of sofas, and are harder for them to reach than end tables. Konchelik also warned against use of dining room table that have aprons which would block wheelchair arms.

Konchelik pointed out other aspects of design to help the elderly. For example, levers are preferable to knobs, wherever possible. An arthritic hand can push or pull a lever much easier than it can twist a knob.

He also suggested stair steps be colored differently, one to the other, to make them more distinct to older people with failing eyes.

Konchelik, interviewed over a telephone from his studio in Ohio, said such ideas are rarely implemented in senior centers, housing complexes or nursing homes, to the detriment of everyone.

"There aren't that many of us," he said. "I'm virtually alone in the product-design field."

He said help has come for the elderly through federal edicts that have made public buildings more accessible and usable by wheelchair users and the blind. But these changes have not affected private-residence design or consumer goods.

Things are beginning to change, however. Konchelik said he has designed and entire line of new elderly-adapted furniture to be manufactured next year. He said he could not identify the manufacturer, however.