What Is Alzheimer’s Disease? What Are The Early Signs of Alzheimer’s In The Eye?

Trouble understanding visual images and spatial relationships. For some people, having vision problems is a sign of Alzheimer’s. This may lead to difficulty with balance or trouble reading. Follow this article to learn more about what the early signs of Alzheimer’s in the eye are.

Alzheimer’s disease is a progressive, degenerative type of brain disease. It’s caused by cell damage and deteriorating changes in the brain. Alzheimer’s erodes memories and thinking skills. It’s a fatal condition that progresses over the course of many years. Aging is the most prevalent risk factor for Alzheimer’s disease. It’s not fully understood why some people get Alzheimer’s and others don’t. It’s known that Alzheimer’s disproportionately affects women and Communities of Color. However, anyone can get Alzheimer’s disease.

If you routinely see an ophthalmologist, you’re probably used to getting standardized eye exams that assess vision and look for conditions like glaucoma and macular degeneration. However, these tests don’t analyze the eye for evidence of Alzheimer’s disease. But there is a test, called Optical Coherence Tomography Angiography (OCTA) — a relatively new, noninvasive imaging test — that allows your ophthalmologist to view tiny blood vessels in the back of your eye.

Follow this article to learn more about the early signs of Alzheimer’s in the eye, its symptoms, causes, and so more.

What is Alzheimer’s disease?

Alzheimer’s disease is the most common type of Alzheimer’s. It is a progressive disease beginning with mild memory loss and possibly leading to loss of the ability to carry on a conversation and respond to the environment. Alzheimer’s disease involves parts of the brain that control thought, memory, and language.

Alzheimer’s is not a normal part of aging. The greatest known risk factor is increasing age, and the majority of people with Alzheimer’s are 65 and older. Alzheimer’s disease is considered to be younger-onset Alzheimer’s if it affects a person under 65. Younger-onset can also be referred to as early-onset Alzheimer’s. People with younger-onset Alzheimer’s can be in the early, middle or late stage of the disease.

Alzheimer’s worsens over time. Alzheimer’s is a progressive disease, where Alzheimer’s symptoms gradually worsen over a number of years. In its early stages, memory loss is mild, but with late-stage Alzheimer’s, individuals lose the ability to carry on a conversation and respond to their environment. On average, a person with Alzheimer’s lives 4 to 8 years after diagnosis but can live as long as 20 years, depending on other factors.

Alzheimer’s has no cure, but one treatment — aducanumab (Aduhelm) is the first therapy to demonstrate that removing amyloid, one of the hallmarks of Alzheimer’s disease, from the brain is reasonably likely to reduce cognitive and functional decline in people living with early Alzheimer’s. Other treatments can temporarily slow the worsening of Alzheimer’s symptoms and improve quality of life for those with Alzheimer’s and their caregivers. Today, there is a worldwide effort underway to find better ways to treat the disease, delay its onset and prevent it from developing.

What are the symptoms of Alzheimer’s disease?

Whether you’re concerned for yourself or someone you care about, it’s important to know the warning signs of Alzheimer’s so you can ensure an early diagnosis. Here are 10 of the most common warning signs for Alzheimer’s:

  • Memory loss
  • Difficulty in performing familiar tasks
  • Problem in language
  • Difficulty in remembering the time and place
  • Impaired judgment
  • Facing difficulty while thinking
  • Misplacing things
  • Changes in mood and behavior
  • Personality changes
  • Loss of initiative

Memory loss:

One of the most common signs of Alzheimer’s disease, especially in the early stage, is forgetting recently learned information. Others include forgetting important dates or events, asking the same questions over and over, and increasingly needing to rely on memory aids (e.g., reminder notes or electronic devices) or family members for things they used to handle on their own.

Difficulty in performing familiar tasks:

People with Alzheimer’s often find it hard to complete daily tasks. Sometimes they may have trouble driving to a familiar location, organizing a grocery list or remembering the rules of a favorite game.

Problem in language:

People living with Alzheimer’s may have trouble following or joining a conversation. They may stop in the middle of a conversation and have no idea how to continue or they may repeat themselves. They may struggle with vocabulary, have trouble naming a familiar object or use the wrong name.

Difficulty in remembering the time and place:

People living with Alzheimer’s can lose track of dates, seasons and the passage of time. They may have trouble understanding something if it is not happening immediately. Sometimes they may forget where they are or how they got there.

Impaired judgment:

Individuals may experience changes in judgment or decision-making. For example, they may use poor judgment when dealing with money or pay less attention to grooming or keeping themselves clean.

Facing difficulty while thinking:

From time to time, people may have difficulty with tasks that require abstract thinking, such as using a calculator or balancing a checkbook. However, someone living with Alzheimer’s may have significant difficulties with such tasks because of a loss of understanding what numbers are and how they are used.

Misplacing things:

A person living with Alzheimer’s disease may put things in unusual places. They may lose things and be unable to go back over their steps to find them again. He or she may accuse others of stealing, especially as the disease progresses.

Changes in mood and behavior:

Individuals living with Alzheimer’s may experience mood and personality changes. They can become confused, suspicious, depressed, fearful or anxious. They may be easily upset at home, with friends or when out of their comfort zone.

Personality changes:

Personalities can change in subtle ways over time. However, a person living with Alzheimer’s may experience more striking personality changes and can become confused, suspicious or withdrawn. Changes may also include lack of interest or fearfulness.

Loss of initiative:

A person living with Alzheimer’s disease may experience changes in the ability to hold or follow a conversation. As a result, he or she may withdraw from hobbies, social activities or other engagements. They may have trouble keeping up with a favorite team or activity.

What are the causes of Alzheimer’s disease?

Several processes occur in Alzheimer’s disease, including amyloid plaque deposits, neurofibrillary tangles and neuronal death.

  • Amyloid plaques are deposits outside the brain cells — they prevent the brain from passing signals properly.
  • Neurofibrillary tangles are deposits inside the brain cells — they kill the cells by blocking off food and energy, causing Alzheimer’s that worsens over time.
  • Neuronal death causes shrinking in the outer layer of the brain (the cortex) which is vital to memory, language and judgment — Alzheimer’s disease is characterized by this shrinkage.

In most cases, scientists are still unsure of what triggers the formation of plaques, tangles and other chemical changes associated with sporadic Alzheimer’s disease. Suspected causes include environmental factors, chemical imbalances or the body’s own immune system.

Alzheimer’s disease tends to target the outer part of the brain first, which is associated with learning and short-term memory. As the disease progresses deeper into the brain, other functions are affected and symptoms get worse.

For people with familial Alzheimer’s disease, mutations in 3 genes have been found to increase the production of amyloid plaques that damage the brain. There are other ‘risk-factor genes’ that may increase a person’s chance of getting Alzheimer’s disease earlier in life.

What are some of the modifiable risk factors of Alzheimer’s disease?

Although we can’t change our genes or stop aging, there are changes that we can make to reduce our risk of Alzheimer’s, either lifestyle changes as individuals or wider changes across society. A growing body of research evidence exists for 12 potentially modifiable risk factors. We might prevent or delay up to 40% of cases of Alzheimer’s, if we were able to modify all of the risk factors.

Although behavior change is difficult and some associations might not be causal, individuals have a huge potential to reduce their Alzheimer’s risk. Many of the risk factors are also shared with other non-communicable diseases such as heart disease, cancer, diabetes and chronic respiratory diseases.

Keeping active, eating well and engaging in social activities all promote good brain health and may reduce your risk of developing Alzheimer’s. Keeping your heart healthy, including by avoiding smoking and excessive alcohol consumption, can lower your risk of Alzheimer’s and other diseases too.

The following is a list of risk factors for Alzheimer’s along with suggestions of how to counteract them and reduce risk.

  • Physical inactivity
  • Smoking
  • Alcohol consumption
  • Head injury
  • Air pollution
  • Loss of social contact
  • Less education
  • Obesity
  • Hypertension
  • Diabetes
  • Depression
  • Hearing impairment

Physical inactivity:

Regular physical activity is one of the best ways to reduce your risk of Alzheimer’s. It’s good for your heart, circulation, weight and mental wellbeing. It is recommended that adults aim for either 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity each week.


Smoking greatly increases your risk of developing Alzheimer’s. You’re also increasing your risk of other conditions, including type 2 diabetes, stroke, and lung and other cancers. It’s never too late – stopping smoking later in life also reduces the risk of Alzheimer’s.

Alcohol consumption:

Alcohol misuse and drinking more than 21 units weekly increase the risk of Alzheimer’s. The harmful use of alcohol is a causal factor in more than 200 disease and injury conditions. There is a causal relationship between harmful use of alcohol and a range of mental and behavioral disorders, other noncommunicable diseases as well as injuries.

Head injury:

Head injuries are most commonly caused by car, motorcycle, and bicycle accidents; military exposures; boxing, football, hockey and other sports; firearms and violent assaults; and falls. Policymakers should use public health and other policy measures to reduce head injuries.

Air pollution:

A growing amount of research evidence shows that air pollution increases the risk of Alzheimer’s. Policymakers should expedite improvements in air quality, particularly in areas with high air pollution.

Loss of social contact:

It is well established that social connectedness reduces the risk of Alzheimer’s. Social contact enhances cognitive reserve or encourages beneficial behaviors. There is not much evidence for any specific activity protecting against Alzheimer’s. Joining a club or community group are good ways to stay socially active.

Less education:

A low level of education in early life affects cognitive reserve and is one of the most significant risk factors for Alzheimer’s. Policy should prioritize childhood education for all.


Particularly in mid-life, obesity is associated with an increased risk of Alzheimer’s. Obesity is also associated with other NCDs and can generally be addressed through lifestyle changes such as diet and exercise.


Hypertension (high blood pressure) in mid-life increases a person’s risk of Alzheimer’s, as well as causing other health problems. Medication for hypertension is the only known effective preventive medication for Alzheimer’s.


Type 2 diabetes is a clear risk factor for development of future Alzheimer’s. Whether any particular medication helps with this is unclear, but treatment of diabetes is important for other health reasons.


Depression is associated with Alzheimer’s incidence. Depression is part of the prodrome of Alzheimer’s (a symptom that occurs before the symptoms that are used for diagnosis). It is not clear to what extent Alzheimer’s may be caused by depression or the reverse, and both may be the case. In any case, it is important to manage and treat depression because it is associated with increased disability, physical illnesses and worse outcomes for people with Alzheimer’s.

Hearing impairment:

People with hearing loss have a significantly increased risk of Alzheimer’s. Using hearing aids seems to reduce the risk. As hearing loss is one of the risk factors which affects the most people, addressing it could result in a large impact on the number of people developing Alzheimer’s.

What are the stages of Alzheimer’s disease?

The symptoms of Alzheimer’s disease worsen over time, although the rate at which the disease progresses varies. On average, a person with Alzheimer’s lives four to eight years after diagnosis, but can live as long as 20 years, depending on other factors. Changes in the brain related to Alzheimer’s begin years before any signs of the disease. This time period, which can last for years, is referred to as preclinical Alzheimer’s disease.

The stages below provide an overall idea of how abilities change once symptoms appear and should only be used as a general guide. (Dementia is a general term to describe the symptoms of mental decline that accompany Alzheimer’s and other brain diseases.)

The stages are separated into three categories: mild Alzheimer’s disease, moderate Alzheimer’s disease and severe Alzheimer’s disease. Be aware that it may be difficult to place a person with Alzheimer’s in a specific stage as stages may overlap.

Early stage Alzheimer’s – Mild:

In the early stage of Alzheimer’s, a person may function independently. He or she may still drive, work and be part of social activities. Despite this, the person may feel as if he or she is having memory lapses, such as forgetting familiar words or the location of everyday objects.

Symptoms may not be widely apparent at this stage, but family and close friends may take notice and a doctor would be able to identify symptoms using certain diagnostic tools. Common difficulties include:

  • Coming up with the right word or name.
  • Remembering names when introduced to new people.
  • Having difficulty performing tasks in social or work settings.
  • Forgetting material that was just read.
  • Losing or misplacing a valuable object.
  • Experiencing increased trouble with planning or organizing.

Mild stage Alzheimer’s – Moderate:

Middle-stage Alzheimer’s is typically the longest stage and can last for many years. As the disease progresses, the person with Alzheimer’s will require a greater level of care. During the middle stage of Alzheimer’s, the dementia symptoms are more pronounced. the person may confuse words, get frustrated or angry, and act in unexpected ways, such as refusing to bathe.

Damage to nerve cells in the brain can also make it difficult for the person to express thoughts and perform routine tasks without assistance. Symptoms, which vary from person to person, may include:

  • Being forgetful of events or personal history.
  • ​Feeling moody or withdrawn, especially in socially or mentally challenging situations.
  • Being unable to recall information about themselves like their address or telephone number, and the high school or college they attended.
  • Experiencing confusion about where they are or what day it is.
  • Requiring help choosing proper clothing for the season or the occasion.
  • Having trouble controlling their bladder and bowels.
  • Experiencing changes in sleep patterns, such as sleeping during the day and becoming restless at night.
  • Showing an increased tendency to wander and become lost.
  • Demonstrating personality and behavioral changes, including suspiciousness and delusions or compulsive, repetitive behavior like hand-wringing or tissue shredding.

In the middle stage, the person living with Alzheimer’s can still participate in daily activities with assistance. It’s important to find out what the person can still do or find ways to simplify tasks. As the need for more intensive care increases, caregivers may want to consider respite care or an adult day center so they can have a temporary break from caregiving while the person living with Alzheimer’s continues to receive care in a safe environment.

Late stage Alzheimer’s – Severe:

In the final stage of the disease, dementia symptoms are severe. Individuals lose the ability to respond to their environment, to carry on a conversation and, eventually, to control movement. They may still say words or phrases, but communicating pain becomes difficult. As memory and cognitive skills continue to worsen, significant personality changes may take place and individuals need extensive care. At this stage, individuals may:

  • Require around-the-clock assistance with daily personal care.
  • ​Lose awareness of recent experiences as well as of their surroundings.
  • Experience changes in physical abilities, including walking, sitting and, eventually, swallowing.
  • Have difficulty communicating.
  • Become vulnerable to infections, especially pneumonia.

The person living with Alzheimer’s may not be able to initiate engagement as much during the late stage, but he or she can still benefit from interaction in ways that are appropriate, like listening to relaxing music or receiving reassurance through gentle touch. During this stage, caregivers may want to use support services, such as hospice care, which focus on providing comfort and dignity at the end of life. Hospice can be of great benefit to people in the final stages of Alzheimer’s and other dementias and their families.

Can Alzheimer’s affect your eyes?

A person’s eyesight can identify the disease even before they develop the symptoms. If the retinal nerve of the eye that comes out of the brain becomes narrower, they may have the onset of Alzheimer’s disease. The beta-amyloid protein accumulation in the brain is the first noticeable sign of Alzheimer’s. They start to develop 15 to 20 years before the onset of Alzheimer’s and can be identified through brain imaging techniques.

The thickness of the retina can be examined to confirm the disease, as patients with Alzheimer’s disease will have thinner retina. You can experience blurry vision, which leads to the loss of sharpness of eyesight, making the objects you see appear out of focus or foggy.

Alzheimer’s disease can affect vision. Vision is a complicated process, in which visual information is sent from our eyes to our brain, where images are interpreted. Various factors contribute to how our brains interpret images, including memories and thoughts. Alzheimer’s can affect vision in various ways. Certain diseases that affect the brain, including Alzheimer’s, can influence the brain’s interpretation of images being received by the eyes.

In addition, vision problems, such as cataracts or changes in eyesight, can make it even more difficult for people with Alzheimer’s or dementia to navigate their world. Sadly, decreased visual perception can lead to misinterpretation of situations and create safety risks for people with Alzheimer’s and dementia.

What are the early signs of Alzheimer’s in the eye?

Alzheimer’s is a progressive disorder that causes significant damage to the brain. The brain controls many vital functions in the body, including vision. Since it can cause numerous ocular defects, visual impairment is one of the first warning signs of Alzheimer’s. Some of the visual defects caused by Alzheimer’s are:

  • Difficulty in object recognition
  • Poor color discrimination
  • Impaired peripheral vision
  • Loss of perception
  • Loss of spatial awareness

Difficulty in object recognition:

Often, those with Alzheimer’s can’t identify the objects that they see. Experts say that the eyes can see the thing as it is, but their brain misinterprets it.

Poor color discrimination:

Alzheimer’s patients find it difficult to distinguish different colors from one another. This is especially true for colors in the blue-violet range. Contrasting colors are needed to simplify daily tasks.

Impaired peripheral vision:

Damaged peripheral vision is a common occurrence in those with Alzheimer’s. They typically have a progressive decline in side-vision. There will be a big chance that the person might not see objects to their sides, making them prone to accidents.

Loss of perception:

The ability to see the world around us in three dimensions is referred to as depth of perception. Alzheimer’s patients may be unable to distinguish between flat objects and three-dimensional objects. For instance, they may be unable to see a white plate on a white table. They would only see a flat, white surface.

Loss of spatial awareness:

Alzheimer’s patients may lack spatial awareness. Judging how far an object is would prove to be problematic. They may reach for an item that is in front of them and miss it entirely.

How can you keep Alzheimer’s at bay?

Healthcare providers typically advise older adults to make certain lifestyle changes to keep cardiovascular disease, diabetes, and cancer at bay. Researchers have come to realize these lifestyle changes also inhibit the development of Alzheimer’s disease. Here are a few ways seniors can reduce their risk of Alzheimer’s disease.

  • Physical exercise
  • Mental gymnastics
  • Healthier diet
  • Quality sleep
  • Quit smoking
  • Prevent injury

Physical exercise:

Physical activity exercises the heart and enhances blood flow to the brain. Exercise dilates blood vessels and allows oxygenated blood and nutrients to nourish brain cells. Neurons are then able to perform various functions better. Seniors should engage in activities that elevate the heart rate for at least 30 minutes three times each week.

Mental gymnastics:

Engaging in various mental activities allows neurons to build new pathways of communication. This way, if some pathways get blocked, messages find their way around using other links. To exercise their minds effectively, seniors should find activities that offer different types of challenges. These activities might include playing board, card, or video games or putting together puzzles. Seniors should take classes in a particular area of interest or learn a new hobby.

Healthier diet:

The Mediterranean and the Dietary Approaches to Stop Hypertension (DASH) diets are often recommended for boosting cardiovascular and brain health. These diets include:

  • Fish, shellfish, and poultry
  • Limited amounts of red meat
  • Fruits and vegetables, especially red, blue, and purple varieties
  • Whole grains
  • Nuts
  • Olive oil and other healthy fats

Quality sleep:

Researchers from the University of Toronto learned that sound, restful sleep interferes with the APOE e4 gene, which commonly leads to the development of Alzheimer’s. One study involved 700 male and female seniors whose cognitive status and sleep patterns were monitored over six years.

Seniors who had the gene but who also enjoyed restful sleep had higher levels of memory and thinking ability. Out of the 700 seniors, 98 were eventually diagnosed with Alzheimer’s disease. When researchers studied the brains of the deceased, they found more tangles and a greater degree of damage in the seniors who did not achieve restful sleep at night.

Quit smoking:

The chemicals found in tobacco constrict blood vessels, interfere with blood circulation, and affect blood pressure. Inadequate blood flow deprives the brain of oxygen and essential nutrients.

Prevent injury:

Brain injury increases the risk of cognitive decline. Keep indoor and outdoor pathways clear to prevent falls and possible head injuries. When driving or riding as a passenger in a vehicle, seniors should wear their seat belts. When riding a bike or playing contact sports, they should wear helmets.

How can you care for someone with Alzheimer’s disease?

Caring for someone with Alzheimer’s disease can be hard — but also rewarding. Your emotional and physical support will be a great help when the person’s world seems confusing and hostile. Take advantage of the community support that’s available for people with Alzheimer’s disease, their families and carers. Following are some of the points that could help you in taking care of your loved ones:

  • Coordinate their care
  • Plan ahead
  • Take care of yourself

Coordinate their care:

Because Alzheimer’s disease gets progressively worse, your loved one will need more care as time goes on. It can be helpful to designate one person who coordinates care and helps them put together a care plan.

Plan ahead:

It is wise to plan early for the future. Encourage the person to arrange for a trusted person to manage their affairs through a power of attorney, and to draw up an advanced care directive explaining what treatments they would prefer if they become unable to give consent later on.

Take care of yourself:

Looking after a loved one with Alzheimer’s disease can be tough and draining. Make sure you spend time socializing and meeting other people. Find activities and interests you can draw encouragement from. Give yourself space to rest, accept and appreciate your loved one.


Currently, many people living with Alzheimer’s disease are cared for at home by family members. Caregiving can have positive aspects for the caregiver as well as the person being cared for. It may bring personal fulfillment to the caregiver, such as satisfaction from helping a family member or friend, and lead to the development of new skills and improved family relationships.

Although most people willingly provide care to their loved ones and friends, caring for a person with Alzheimer’s disease at home can be a difficult task and may become overwhelming at times. Each day brings new challenges as the caregiver copes with changing levels of ability and new patterns of behavior. As the disease gets worse, people living with Alzheimer’s disease often need more intensive care.