Two years ago, Ed Hunt, an 80-year-old widower, spent most of his time alone in his 10th-floor Rhode Island apartment watching television and staring out the window. He walked unsteadily with a cane and suffered tremors caused by Parkinson's disease.

His son and daughter-in-law wanted Hunt to come live with them in Virginia, but they feared he wouldn't be able to feed or care for himself while they worked. They didn't like the idea of a nursing home, especially because Hunt was so mentally alert, but it seemed the only alternative.

Today, Hunt lives happily in Fairfax County with his family. They share breakfasts and dinner, but in between, five days a week, Ed Hunt leaves the house to join a new group of friends at the Annandale Elderly Daycare Center in Fairfax County.

There, instead of staring at the television, Hunt can play bingo, join a sing-along, watch a movie or work in the crafts shop. "I wouldn't miss it for all the tea in China," he says. "It's a friendly crowd of people. You just couldn't ask for more."

For the Hunts and other families, the center has proven an attractive and affordable alternative to nursing home care. The Annandale center is Fairfax's first. It opened its doors four years ago, and has proven so popular that the county has plans to open two more. That expansion is just a small part of a nationwide trend as communities begin to cope with the changing demographics of an aging America.

"Communities have recognized, I think, a gap in their service system," said Betty Ransom, a spokeswoman for the National Institute on Adult Daycare. "They have senior centers for the more able, home care for the bed-bound and nursing homes for those who need 24-hour care.

"Then we have this population that doesn't need 24-hour care. They're too fragile to be alone all the time; they just need some additional support to maintain their independence."

In the years ahead, the need for that care is expected to increase dramatically. Since 1960, the number of Americans over age 85 has increased by 165 percent. By the year 2020, according to officials at the Annandale center, Americans over age 65 will outnumber teen-agers by a ratio of two to one.

There are now at least 1,000 adult care centers around the country, and more are planned. The four-year-old Annandale center has proven so popular that it has a three-month waiting list for its two dozen slots.

"A lot of people don't realize this kind of day care is available," said Joan LeGallo, coordinator of the county's Information and Referral Program. "But we do have frequent requests."

At Annandale, Hunt eats meals planned by a nutritionist, is watched over by two registered nurses and a recreational therapist, and can consult with a variety of specialists and counselors trained especially in the care of older people.

The center is administered by the county Health department and operated with county funds. Center members are charged only what they can afford, and 40 percent of the two dozen or so who come each day pay nothing.

Participants must live in Fairfax County, Fairfax City or Falls Church. They must be age 60 or over, but the average age is 84. Most are women, and close to half suffer some degree of mental impairment, according to Kay Larmer, a registered nurse and the program director.

The center's elderly members, as well as their families, say they have found it irreplaceable.

"I like the movies and all the amusement that we have here," said Chester Whalen, 80, a retired ambulance driver and embalmer. "The parties."

"I don't think that I would be lonely if I didn't come here," said Erma Kendall, 84, a retired dry cleaning shop worker who moved here from Kansas to be with her daughter. "But I might get senile. I would get narrow. I wouldn't have the contacts. You just need the outside world, sometimes."

For the families of these people, day care is often seen as a respite from the constant demands of caring for the elderly relatives, as well as a less expensive alternative to private homes, which in the Fairfax area can cost as much as $2,000 a month.

"The center has filled a real gap," said Ed Hunt's son, Warren, deputy director of engineering and construction for the Fairfax County Water Authority. "I don't know what we would have done without it."

Jim Bruner takes his wife, June, to the center two days a week. June Bruner, 67, suffers from Alzheimer's disease and requires constant care.

"If there's a little bit of heaven," Bruner said, "it's the Annandale day care center."