Untreated vision problems can increase dementia risk

As the population ages, the number of people in the U.S. with dementia continues to climb. According to the Centers for Disease Control and Prevention (CDC), 5.8 million adults in the U.S. currently live with Alzheimer's disease and related dementias. That number is expected to hit 14 million by 2060.

Currently, there is no cure or effective drug treatment for dementia. Some risk factors for dementia, such as genetics and family history, lie beyond our control. Modifiable factors, however, are things we can act on.

Public health experts and researchers are emphasizing the importance of addressing modifiable risk factors, including untreated high blood pressure, hearing loss and smoking. A study published recently in JAMA Neurology has uncovered one more modifiable risk factor: vision problems.

This research adds to the growing evidence that fading eyesight is a risk factor for developing dementia. Researchers estimate that about 62% of current dementia cases could have been prevented across risk factors and that 1.8% — close to 100,000 cases — could have been prevented through healthy vision.

While that might seem like a small percentage, it represents a comparatively easy fix. Eye exams, eyeglass prescriptions and cataract surgery are relatively inexpensive — and more accessible — compared to other interventions or the long-term care people with dementia often require.

Sensory impairment and cognition
While the study suggests there could be a link between dementia and poor eyesight, the connection isn’t fully understood. It’s possible that a reduced ability to see day-to-day life leads to a lower amount of cognitive stimulation.

Like poor hearing, poor vision is a form of sensory deprivation, in which the brain is getting limited stimulation. Whether it’s through the senses or through cognitively stimulating activities, such as learning a new language or doing crossword puzzles, stimulation of the brain has been linked to a lower risk of developing dementia.

Regular social interactions are also linked to a lower risk of dementia. However, poor vision can limit older adults’ ability to participate in physical and social activities and result in social isolation.

An older adult who can’t see well may be reluctant to leave the house or drive to see friends. Someone who enjoys weekly bridge meetups, for example, may stop attending if they have difficulty seeing the cards.

Keep an eye on your vision
According to Dr. Allison Pierce, an optometrist with Sharp Rees-Stealy Medical Group, as people age, their vision changes. They are more susceptible to developing age-related eye conditions.

“After age 40, the eye is less able to accommodate or change focus to different distances,” Dr. Pierce says. “Visual correction for distance and reading focus may be needed, which can be helped with bifocals, reading or progressive lenses.”

Cataracts are the most common eye condition associated with aging. Cataracts are due to the natural aging process of the clear lens inside the eye and can be aggravated by other factors. Older adults also have an increased risk of glaucoma, dry eye and macular degeneration.

“Annual eye exams are recommended for everyone, but essential for seniors,” Dr. Pierce says. “Early detection of these diseases can be found at routine eye exams, allowing for early treatment to slow or prevent vision loss and discomfort.”

Tips to preserve eyesight
In addition to regular eye exams, there are other actions that can be taken to preserve eyesight. These include:

• Eating a well-balanced diet

• Quitting smoking

• Keeping active

• Protecting your eyes from the sun

“The number one recommendation I give my patients to slow the aging of the eyes is to wear sunglasses or other sun protection when outdoors,” says Dr. Pierce. “Most of the conditions associated with aging, such as cataracts and macular degeneration, are caused or aggravated by UV exposure over time.”

Finding ways to prevent or delay the onset of dementia could help reduce its devastating impact on the lives of affected individuals and their families, Dr. Pierce says. Spotting modifiable risk factors is a critical first step for developing effective interventions.