- Barbara Pierscionek
- The conversation*
Scientists from the University of California, San Diego, USA, have developed a mobile application capable of detecting the first signs of diseases such as Alzheimer’s disease or other neurological conditions. This tool uses the smartphone camera to track changes in pupil size at a sub-millimeter level.
These assessments can be used to check a person’s cognitive status.
As technology advances, the eyes can become increasingly useful in diagnosing all sorts of diseases and conditions because, being transparent, they require much less invasive methods of examination than other parts of the body.
But even without technology, it’s possible to detect a range of health conditions just by looking into the eyes.
These are some of the warning signs.
The pupil reacts instantly to light, becoming smaller in bright environments and larger in dimly lit environments.
Slow or delayed responses in pupil size can indicate a number of diseases, including some serious conditions such as Alzheimer’s disease, as well as drug effects or evidence of drug use.
Dilated pupils are common in those who use stimulants such as cocaine and amphetamines. Very small pupils can be seen in heroin users.
Red or yellow eyes
A change in color of the sclera (the “whites of the eyes”) may suggest something is wrong.
A red, bloody eye may reflect excessive alcohol or drug use.
It can also be caused by irritation or infection, which in most cases goes away within a few days.
If the color change is persistent, it could indicate a more serious infection, inflammation, or a reaction to wearing contact lenses or their solutions.
In extreme cases, a red eye can indicate glaucoma, a condition that can lead to blindness.
When the sclera turns yellow, it’s usually a very clear sign of jaundice and liver disease.
The underlying causes of jaundice vary widely. These include inflammation of the liver (hepatitis), genetic or autoimmune diseases, allergies to certain drugs, viruses or tumors.
A blood-red spot on the white of the eye (subconjunctival hemorrhage) can look scary and is always the result of a small blood vessel that has ruptured.
Most of the time there is no known cause and it disappears within a few days.
However, it can also be a sign of high blood pressure, diabetes, or blood clotting disorders that cause excessive bleeding.
Blood-thinning medications like aspirin can also cause it. If the problem is frequent, it may be essential for a doctor to review the dosage of the drug.
Ring around the cornea
A white or gray ring around the cornea may be linked to high cholesterol and an increased risk of heart disease.
It can also reveal alcoholism and is sometimes seen in the eyes of the elderly, which is why the medical name given to it is arch senile.
Sometimes the most alarming features that can appear in the eyes are actually the most benign and easily treated.
A pinguecula is a yellowish fatty nodule that can appear on the white of the eye. It is a small fat and protein deposit that can be easily removed with eye drops or removed with a simple operation.
The pterygium, also known as “eye flesh” or “cropped flesh”, is a pinkish growth on the white part of the eye. It is not a vision hazard until it begins to grow on the cornea (the colored part of the eye).
Fortunately, the pterygium grows very slowly and, like the pinguecula, can be easily removed. It must be removed long before it reaches the cornea.
If it continues to grow, the pterygium can form an opaque “film” on the cornea that obstructs vision.
One of the main factors responsible for pinguecula or pterygium is thought to be chronic exposure to ultraviolet light from the sun.
Bulging eyes can be part of a normal facial feature.
But when the eyes weren’t swollen and started to protrude forward, the most obvious cause could be a problem with the thyroid gland and requires medical attention.
A single protruding eye can be caused by an injury, infection or, more rarely, a tumor behind the eye.
Swollen or floating eyelids
The eyelids can also indicate certain diseases, mainly related to minor conditions of the glands of the eyelids.
A common condition is an eye chalazion or ‘stye’ – as it is popularly called – which appears as a red lump on the upper eyelid and, less often, on the lower eyelid. It is caused by a blocked sebaceous gland.
It usually goes away on its own or with warm water compresses. If it persists, it should be removed with a simple procedure.
Eyelid tremor (ocular myokymia) can be caused by irritation or even heat. It often looks much worse than it actually is.
In most cases, it is perfectly harmless and can also be linked to stress, nutritional imbalance or excessive caffeine consumption.
This article is only a guide. If in doubt about your health, it is essential to consult a specialist.
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