The idea took shape as Dr. Shawn Barnes, a psychiatry resident at the University of California, San Diego, watched some hospitalized older patients struggling with consent forms.

It wasn’t because they didn’t understand the forms, or questioned the treatments they were about to undergo. “They had difficulty signing the forms because they had trouble seeing,” Dr. Barnes said. People had donated books for recuperating patients to read in the hospital, but poor eyesight often put those off-limits, too.

The geriatric psychiatry unit kept a few pairs of hand-me-down reading glasses in a drawer, but not enough. “I looked into it and found out they were incredibly cheap,” Dr. Barnes said. “You can buy them online for a buck a pair.”

Hence his call, in an article published in the American Journal of Alzheimer’s Disease and Other Dementias, for facilities that treat older adults to maintain a stockpile of cheap standard reading glasses, the kind drugstores sell.

File under: Simple, Inexpensive Ideas That Could Pay Off. As Dr. Barnes and coauthor Daniel D. Sewell point out, presbyopia — the eye’s inability to focus on nearby objects as the lens stiffens — becomes nearly universal at older ages. But the lenses that correct it don’t require exams and prescriptions; you can pretty much predict what strength someone needs by age.

For older people, several studies have shown, visual impairment in a hospital or nursing home is linked to cognitive decline and delirium.

In a large study of elderly Mexican-Americans in five Southwestern states, for example, those with uncorrected presbyopia scored significantly lower on a commonly used test of cognitive impairment. Problems with distance vision didn’t show the same correlation.

The unfamiliarity, disrupted routines, lack of sleep and new medications added during hospitalization are dangerous to frail elders. “Not being able to see adds to the general confusion,” Dr. Barnes said. “‘Where am I? What is this room?’”

“Things can escalate from there” to agitation or belligerence, Dr. Barnes added.

Sometimes, older patients simply forget to take their reading glasses when an ambulance or a relative brings them to a hospital. Those with dementia may have lost their glasses, or never had any because they can’t explain that they can’t see.

Providing reading glasses won’t solve all vision-related problems in hospitals, of course. Many older patients need prescription lenses.

(To help keep elders oriented and to reduce the odds of delirium, family members should always bring their eyeglasses, hearing aids, dentures and walkers to the hospital, along with family photos and other familiar objects.)

But at 90 cents or so per pair — less than a plastic bedpan or a pair of non-skid socks — “there should be a stock of these, like other hospital supplies,” Dr. Barnes said. “They could be borrowed and returned or just given away.”

The San Diego Depression and Bipolar Support Alliance recently donated more than 150 pairs of reading glasses to the geropsychiatry unit at the University of California, San Diego, Medical Center, he reported. Bravo. And perhaps while we’re waiting through the often-pokey pace of change at hospitals, other advocacy and charitable groups will step up.

And then there’s Dr. Barnes’s next idea for augmenting supplies for the hospitalized elderly: comfortable earplugs, “so patients can get a night’s sleep, even with the beeping and alarms going off and people coming in to talk to the person in the next bed.” They might cost even less than reading glasses.