Older people with visual impairment who undergo cataract surgery report less dizziness, but may be at the same risk of falls as before the surgery, according to a new study.

You would have expected the fall rate to improve, said senior author David B. Elliott of the Bradford School of Optometry and Vision Science at the University of Bradford in West Yorkshire, U.K.

Decreased dizziness and improved vision after cataract surgery lower the chances of tripping over small objects, but getting multifocal lenses after cataract surgery blurs the lower visual field, and adapting to this change might increase the risk of falls, Elliott said.

"The vast majority of cataract occurs in older people and is more prevalent the older you get," he told Reuters Health by email. "As visual impairment approximately doubles the risk of falls and as cataract is one of the main causes of visual impairment in older people, then falls are common in people with cataract."

The researchers analyzed self-reported dizziness and falls before, and six months after, cataract surgery among 287 people whose average age was 76 years. Roughly one third had surgery on their first eye, one third had surgery on their second eye and one third had surgery on both eyes at the same time.

Before surgery, just over half of participants reported dizziness, which declined to 38 percent after surgery. Dizziness seemed to be reduced for people having surgery on their first eye or on both eyes, but not on their second eye, according to the results in Ophthalmic and Physiological Optics.

Before surgery, 23 percent of participants said they had suffered a fall over the past six months, which was similar to the 20 percent who said they fell in the six months following surgery.

Fall risk after surgery was higher if the patient had switched to multifocal spectacles.

Thirty percent of people that started wearing multifocal, or "progressive lenses," after cataract surgery fell, yet only 15 percent of those taken out of progressives fell after surgery, Elliott noted.

"This study presents valuable findings in that falls may be increased indirectly by people commencing wearing multifocal glasses - an identified risk factor for falls," said Professor Stephen Lord, senior principal research fellow of the Falls and Balance Research Group of Neuroscience Research Australia, who was not part of the new study. "Multifocal glasses increase fall risk by blurring the visual field where people need to look as they walk, i.e. about two steps ahead."

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Cataract surgery helps improve all aspects of visually-related activities such as reading, driving and computer work, Elliott said.

It markedly improves vision, reduces vision-related disability and improves quality of life, Lord told Reuters Health by email.

"All surgery has risks, but cataract surgery is one of the safest," Elliott said. "I would strongly recommend it," he said, noting that he even recommended it for his own mother.

"For the vast majority of older people the benefits far outweigh the risks," Lord said. "The implications of this study are that visual management of older people is important."