Eyesight Problems Linked to Dementia: What That Means For You

Aging brings about many different health conditions, ranging from heart disease to vision and hearing loss. But are all these issues just caused by “growing old”? Or could they be caused by something else happening in the background?

The answer here is a complicated one. However, recent studies of the past few years have been shedding evidence on some of the hidden links that were previously missed. The latest news to hit our practice? A new study from February of this year comparing the donated tissue of 86 patients with mental decline. The researchers uncovered retinal changes correlated to changes in areas of the brain responsible for memory and perception of time.

This aligns with a study from last year showing that eyesight and dementia aren’t just happening at the same time, but may be actively impacting one another.

Eyesight, dementia, and Alzheimer’s disease: How are they linked?

In 2022, there were two major studies diving deep into the connection between dementia and eyesight problems.

The first one was published in the Aging & Mental Health journal and was a meta-analysis of past research. The research team compiled the data from 16 other studies that looked at different forms of dementia (such as Alzheimer’s disease, vascular dementia, or Lewy body dementia) and their warning signs.

In total, these studies encompassed 76,373 patients from different continents, providing a very large pool of evidence. Researchers found different types of vision impairment problems are more likely to develop before dementia. In particular, cataracts and diabetes-related eye problems seem to have a strong link with Alzheimer’s disease.

The next study worth looking at was published in the British Journal of Ophthalmology. Here, researchers looked at the link between the speed at which dementia develops, and the onset of other eye conditions using data from the UK Biobank.

Their conclusions were surprisingly specific: age-related macular degeneration (AMD), cataracts, and diabetes-related eye disease all seemed to announce an increased risk of dementia, especially Alzheimer’s disease.

On the other hand, glaucoma didn’t seem to relate to a higher incidence of Alzheimer’s disease at all, but it tended to happen alongside vascular dementia.

Finally, they found an additional part of the puzzle: the link between both conditions was nearly twice as strong in patients who were battling other “systemic conditions” – such as cardiovascular disease, type 2 diabetes, or chronic depression.

So far, the evidence of a link between eyes and minds seems remarkably convincing. But what about the causes? Does dementia cause eye problems, or is it the other way around? Here’s where a lot is still up for debate.

Vision problems and dementia: a “chicken or egg” problem

The studies above are all observational, that is, they limit themselves to seeing what happens, and they draw conclusions from large numbers. As a result, they don’t give us a definite answer about causes, just correlation.

As a result, healthcare experts warn us that there is no simple, single cause behind eye problems and dementia. Instead, the “egg” of the issue will depend on the patient, their surrounding risk factors, and the type of dementia they’re experiencing.

The case for “just age”

The first, traditional explanation is that both problems are just typical of aging. Dementia – the progressive loss of cognitive functioning, including memory, reasoning, language, and ability to perform mental calculations – can happen for a variety of reasons, although most of them involve irreversible changes to the brain. The risk for all dementias increases as you age.

The same is true for most types of vision loss. When it comes to age-related macular degeneration, the cause is even in the name! Likewise, other types of eye health problems develop slowly, from the accumulated damage of intra-ocular pressure on the optic nerve, high blood sugar, or other conditions. Naturally, the risk for any of these climbs with each year of life.

Are vision problems making dementia worse?

The simple answer of “age” doesn’t really match the results from the latest studies. Loss of peripheral vision, problems with depth perception, or blurry vision don’t simply appear just before dementia – they also predict rapidly-progressing cognitive decline.

A possible explanation? The confusion created by vision problems often matches the early signs of dementia, especially Alzheimer’s Disease.

How? Let’s take a look at many of the classic early signs of Alzheimer’s:

• Problems recognizing faces
• Getting lost, even in familiar surroundings
• Frequently missed appointments or misplaced objects
• Problems creating new memories.

Any of these symptoms can become more severe and more noticeable when our brains aren’t receiving proper visual information. To make things more difficult, both dementia and loss of vision tend to progress slowly, making it harder to notice changes from one day to the next.

If we can’t see the objects around us, it will be harder to memorize and recognize faces – especially those of new acquaintances. Maps, schedules, and errand lists can get even harder to recall if you’re already expending extra mental energy in trying to see them properly. As both conditions combine, what may have seemed like simple forgetfulness can quickly precipitate a dementia diagnosis.

The “use it or lose it” theory

According to Dr. Nathaniel Chin, from the Division of Geriatrics and Gerontology in the Department of Medicine at the University of Wisconsin, the connection may go one step further: losing your eyesight doesn’t just worsen your confusion, but it may speed up the changes in your brain responsible for dementia.

According to him, loss of vision will slowly lower the amount of information we feed the brain. In turn, “having less stimulation from vision leads to brain processes breaking down.” After all, the brain often acts like a muscle. If we don’t use our cognitive abilities, we slowly lose them. We become less quick with our reasoning and develop more difficulties with problem-solving.

The other way around: does dementia cause eye problems?

Depending on the type of dementia, we also need to look at the inverse possibility: that the loss of brain function could be behind the loss of vision.

So far, this doesn’t seem to be the case with Alzheimer’s disease. However, when we look at dementia with Lewy bodies (DLW), then yes – dementia itself could be impacting your eyes.

Dementia with Lewy bodies is a specific type of dementia, although it often goes undiagnosed or bundled together with Alzheimer’s, Parkinson’s disease, or age-related cognitive decline. People with Lewy body dementia develop “Lewy bodies,” or small clumps of protein tissue, within their brains.

We don’t know yet why people with LDW start developing these clumps. We do know that the more clumps build up, the bigger the impact on brain function. Often, these bodies can accumulate in the parts of the brain that process what we see. The combination of Lewy body dementia and eyesight problems usually appears as:

• Problems seeing distances or judging the space around you
• Problems calculating the size of objects you see
• Blurry edges, even in nearby objects
• Seeing large floaters or blind spots
• Changes in color vision
• Not being able to make sense of what you see

The catch? In patients with LDW, these symptoms can all develop while leaving your eyes technically intact. This makes it harder to diagnose or treat them, as we don’t know where the Lewy bodies end and any other simultaneous problems, such as cataracts, begin.

What can you do to control dementia and eyesight problems?

In many cases, it may be impossible to pinpoint the exact cause of every problem. However, we can tweak our lifestyles and habits to minimize our risks all around. By protecting your vision, you can help contain the cascade of effects that increase your risk of dementia and cognitive impairment.

The first step is as simple as a yearly comprehensive eye test by our optometrists, especially after age 60. This will help you detect issues quickly and to address them before they worsen. For example, prompt cataract surgery, retinal repairs, and even properly-fitted glasses can help you protect your visual acuity and eye health for longer.

Maintaining your overall physical health also supports healthy eyes and brain. Work with your doctor to keep cholesterol, blood sugar, and high blood pressure under control.

And what if you (or a close relative) just got diagnosed with dementia? Then, it’s important to actively try to slow down its progress. Your neurologist and ophthalmologist should work hand-in-hand here to spot any common eye conditions quickly and in their early stages. Being able to see properly and process what you’re seeing will ensure your quality of life remains untouched for as long as possible.

Assil Gaur Eye Institute: The top facility for eye care in California

The team of experts at AGEI includes eye doctors, surgeons, and technicians who are all committed to improving their patient’s holistic health.

We specialize in highly innovative surgeries that can halt many eye conditions typical of older adults, such as cataracts, glaucoma, retinal detachments, and myopia. We also provide routine eye exams and are happy to work with your family doctor to ensure a welcoming and thorough health care plan.

Please call 866-945-2745 or make an appointment online.

We are conveniently located for patients throughout Southern California and the Los Angeles area at locations in or near Beverly Hills, Santa Monica, West Los Angeles, West Hollywood, Culver City, Hollywood, Venice, Marina del Rey, Malibu, Manhattan Beach, and Downtown Los Angeles