Really, it all boils down to how many cones, or color receptors, you have in your eyes. Advertisement Professor Diana Derval, a neuro-marketing expert, posted an interesting test that has claims. It can lead to eye pain, eye floaters, loss of vision in one or both eyes, and loss of color perception. It doesn’t happen often, but when alcohol is involved, you’re at a higher risk. It doesn’t happen often, but when alcohol is involved, you’re at a higher risk.
They may be the windows to the soul, but eyes can also give a clear view of what's occurring in less ethereal parts of the body. In fact, an eye test could reveal a life or death situation.
As well as detecting vision problems and eye diseases, such as glaucoma or macular degeneration, they can sometimes also reveal whether you're suffering from a number of serious health conditions.
Chairman of the Eyecare Trust, comments: 'Poor uptake of sight tests is probably the biggest risk to the nation's eye health,' she says.
'Around 20 million of us fail to have our sight tested once every two years, yet a simple sight test can detect glaucoma years before you notice lost vision, and many childhood eye conditions which can be permanently corrected if diagnosed early enough.
'Sight tests really are essential health checks.'
Still not convinced? Here's how a simple eye test could help save your life...
1. Diabetes
Around 750,000 people in the UK have undiagnosed diabetes, according to Diabetes UK. Symptoms of Type 2 diabetes can creep up very slowly and are often dismissed as normal tiredness, or just part of growing old, but Dr Schallhorn points out that he's diagnosed cases from eye tests.
High blood-sugar related to diabetes can cause problems in the small blood vessels resulting in diabetic retinopathy, which can lead to blindness. An optometrist will be able to spot early characteristic changes, such as tiny leaks from damaged blood vessels.
'Nowhere are the blood vessels more important than in the retina at the back of the eye,' explains Dr Schallhorn. 'Eyecare professionals have a window to look at this, and we can see very early signs of diabetes and the effect it has on blood vessels in the back of the eye.
'You don't need to go blind with diabetes; it's treatable and the key is to pick it up early,' Dr Schallhorn adds. Not only that, but the sooner diabetes is detected, the sooner it can be treated or managed, meaning other potential complications - including ulcers, kidney and heart damage - can be prevented too.
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2. High blood pressure
Effects of high blood pressure - a condition which affects one in three UK adults but is often symptomless, and is linked with stroke, heart disease and vascular dementia - can sometimes be seen inside the eye.
This is because the force of blood passing through blood vessels in the retina can cause hypertensive retinopathy. Blood vessel walls may thicken, narrowing the vessels and restricting blood from reaching the retina. In some cases, it becomes swollen and its function is limited, and there may be bleeding behind the eye.
3. High cholesterol/Cardiovascular problems
Because of the high blood flow at the back of the eye, excessive cholesterol - which is linked to cardiovascular problems - may also be spotted there, looking like deposits in the blood vessels.
Changes in the patterns of ocular veins and arteries can also be linked to cardiovascular disease and stroke. 'You can see strokes in the eye, and other cardiovascular problems,' says Dr Schallhorn. 'The back of the eye is part of the brain, so anything that can affect the brain can affect the eye - and often they affect the eye first.'
4. Arthritis
Although arthritis is characterised by joint inflammation, autoimmune forms of the disease (like rheumatoid arthritis and ankylosing spondylitis) can affect other parts of the body including the eyes, and the inflammation it causes can be spotted in eye tests.
Dr Schallhorn explains that this inflammation (uveitis) is the same kind that can attack joints. 'It can slowly destroy the eye too,' he says. 'Arthritis is another one of the diseases where eye examinations are important, as the ocular manifestations can have grave consequences if left untreated.'
5. Alzheimer's Disease
Although not available yet, it's hoped that a simple eye test could soon be used to identify the early stages of Alzheimer's disease. Researchers are looking at whether warning signs can be detected using special computer software to analyse images of the eye.
Project co-ordinator Emanuele Trucco, professor of computational vision at the Dundee University, says: 'If you can look into someone's eyes using an inexpensive machine and discover something which may suggest a risk of developing dementia, then that's a very interesting proposition.'
Trucco says the research promises early warning in a non-invasive way, and the test, which will identify differences in the retinal vessels, may even be able to differentiate between different types of dementia.
6. Tumours
The eye has a large blood supply relative to its size, says Dr Schallhorn, and for this reason, certain types of tumours can spread to the eye, as well as primary tumours developing there - although this is rare.
Brain tumours can also be spotted in an eye test, sometimes through swelling of the optic nerve linked to pressure from the tumour.
In This Article
Table of Contents
- Symptoms
- Causes
- Treatment
Sudden vision loss without pain is the most common symptom of a stroke involving your eye. An eye stroke, or anterior ischemic optic neuropathy (AION), is a condition in which blood flow either becomes blocked or reduced to the tissues of the front part of the optic nerve. An eye stroke can cause sudden loss of peripheral vision, distorted vision, and blind spots in your vision, and while it may be frightening, prompt medical attention can prevent or limit vision loss.
Symptoms
People with eye stroke are usually given little warning. Most people with eye stroke notice a loss of vision in one eye upon waking in the morning, with no pain. Some people notice a dark area or shadow in their vision that affects the upper or lower half of their visual field. Other symptoms include loss of visual contrast and light sensitivity.
Depending on the area of the eye where blood flow becomes blocked or reduced, the following occlusions may occur.
- Central retinal artery occlusion (CRAO): This occlusion usually occurs with sudden, profound vision loss in one eye, with no pain. It occurs in the retina.
- Central retinal vein occlusion (CRVO): Usually causing sudden, painless vision loss that can be mild or severe, this blockage occurs in the central retinal vein where it enters the eye.
- Branch retinal artery occlusion (BRAO): This blockage is usually painless and occurs suddenly. The patient usually loses peripheral vision, and sometimes central vision as well. Underlying causes include narrowing of the carotid artery, high blood pressure, cholesterol disorders, and/or cardiac disease.
- Branch retinal vein occlusion (BRVO): This type of blockage causes bleeding and clotting along the retinal vein It may result in decreased vision, peripheral vision loss, distorted vision, or blind spots. This type involves one eye and may be caused by high blood pressure or diabetes.
Giant Cell Arteritis
A dangerous form of AION known as arteritic AION is caused by a condition known as giant cell arteritis (GCA). GCA causes inflammation of medium- and large-sized arteries of the optic nerve as well as those of the scalp. While the cause of GCA is unknown, it typically manifests with a cascade of symptom prior to vision loss, including:
- Fever
- Fatigue
- Pain in the temples
- Pain when chewing
- Scalp pain or tingling
- Neck pain
- Muscle aches and pain in the upper legs or arms
- General fatigue
- Loss of appetite
- Unexplained weight
The key symptom of GCA-associated AION is painless blurriness or vision loss lasting for minutes or hours before the loss becomes permanent. Unless diagnosed and treatedimmediately, the vision loss may be massive and irreversible.
Causes
Eye stroke is caused by poor circulation in the blood vessels that supply the front portion of the optic nerve. The optic nerve is the cable that connects the brain to the eye and carries millions of nerve fibers and blood vessels.
Although an eye stroke can occur from a total blockage of a blood vessel that feeds the optic nerve, it is more commonly caused by a lack of pressure or perfusion of the tissue. Blood pressure may change relative to the eye pressure and the normal flow of blood is reduced. If the optic nerve's nutrient and oxygen supply is cut off, nerve tissue is damaged and lost, resulting in vision loss.
Eye stroke is more common in middle-aged people and the elderly. In fact, less than 10 percent of people affected with AION and GCA-associated arteritic AION are under the age of 45.
Cardiovascular disease raises your risk of developing the disease. In some patients with cardiovascular disease, blood pressure falls markedly while sleeping. This low blood pressure reduces circulation through those arteries, increasing the chance of eye stroke, so reducing your risk of cardiovascular disease can overall help reduce your risk for eye stroke.
Certain optic disc shapes can also raise your risk of eye stroke. Nerve fibers that travel to the brain and down the optic nerve must enter the eye through a hole called the optic foramen. If this hole is smaller than average, the nerve fibers can become crowded. When they become crowded, the risk of developing an occlusion increases.
Although the relationship is not well understood, people who have significant cardiovascular disease and also take the drug Viagra are more at risk for the disease.
Diagnosis
If your doctor suspects eye stroke, he or she will review your medical history and ask about cardiovascular disease and conditions you may have such as diabetes, hypertension, or high cholesterol.
Your blood pressure will be measured, as well as your central visual acuity and visual field. Your doctor will usually dilate your eyes to examine your optic nerve and retina. Your doctor will also examine your optic nerve to check for pale color or possibly optic disc swelling.
Your normal eye will be compared to the affected eye to detect changes. Your doctor will also carefully rule out arteritic ION (a serious eye stroke affecting the optic nerve) and ask about symptoms such as fever, headache, scalp tenderness, jaw pain, weight loss, loss of appetite, and fatigue, so be prepared to discuss these points.
Treatment
Corticosteroids have been shown to increase visual acuity in some cases of eye stroke if started early enough, which is why it's crucial to visit your doctor if you notice sudden changes in your vision.
Corticosteroids reduce leakiness of the vessels and improve swelling and circulation. They are the treatment of choice in AION because it is an eye stroke that appears to be more commonly caused by reduced blood flow and inflammation, as opposed to a true blockage of a blood vessel from a small particle or emboli. Some doctors may also prescribe drugs to lower eye pressure in hopes to improve blood flow to the optic nerve.
Some physicians also feel that newer, more powerful anti-hypertensive medications may reduce blood pressure too low when sleeping, putting people at risk for eye stroke, so make sure to discuss with your doctor if you are on an anti-hypertensive and concerned. There may be a different option available for you.
There has been some research on the potential to prescribe medications that act as neuroprotection, that may regenerate nerve fibers in the optic nerve. However, there is no conclusive evidence that these drugs provide any benefit. Other treatment is aimed at controlling cardiovascular risk factors so eye stroke does not occur to the other eye, as there is a 30 percent chance that it will happen to the other eye within three years.
A Word From Verywell
Eye stroke is a potentially visually devastating eye disease. Having high blood pressure and carotid artery disease increases your risk of experiencing an eye stroke, so it's important to take the necessary steps to make sure those conditions are in check.
When to See a Doctor
If you experience sudden vision loss of any sort, see your doctor immediately or go to the nearest emergency room. Prompt treatment—delivered within hours, not days—is essential to preventing vision loss, particularly if GCA is involved.
- Janigian, R. American Academy of Opthalmology. Eye Smart. 2015.