- Barbara Pierscionek
- The Conversation*
12 May 2022
Scientists at the University of California at San Diego, in the United States, have developed a mobile application that can detect the first signs of diseases such as Alzheimer’s or other neurological conditions. This tool uses the smartphone’s camera to track changes in pupil size at a submillimetre level.
These assessments can be used to check a person’s cognitive condition.
As technology evolves, the eyes may become increasingly useful as a means of diagnosing all kinds of diseases and conditions because, being transparent, they require much less invasive examination methods than other parts of the body.
But even without technology, it is possible to detect a range of health problems simply by looking into the eyes.
These are some of the warning signs.
the pupil size
The pupil instantly responds 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, as well as pointing out drug effects or evidence of drug use.
Dilated pupils are common in those who use stimulant drugs such as cocaine and amphetamines. Very small pupils can be seen in heroin users.
Red or yellow eyes
A change in the color of the sclera (the “white of the eyes”) can suggest that something is wrong.
A red, bloody eye may reflect excessive consumption of alcohol or drugs.
This can also be caused by an irritation or infection which, in most cases, passes 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 disease that can lead to blindness.
When the sclera turns yellow, it is usually a very clear sign of jaundice and liver disease.
The underlying causes of jaundice vary widely. They include inflammation of the liver (hepatitis), genetic or autoimmune diseases, allergies to certain drugs, viruses or even tumors.
A blood-red spot on the white of the eye (subconjunctival hemorrhage) can look frightening 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.
Anticoagulant medications such as aspirin can also be the cause. If the problem is frequent, it may be critical for a doctor to review the medication dosage.
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 older people, 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 easy to treat.
A pinguecula is a yellowish fatty nodule that can appear on the white of the eye. It is a small deposit of fat and protein that can be easily remedied with eye drops or removed with a simple operation.
Pterygium, also known as “eye flesh” or “grown flesh”, is a pinkish growth on the white part of the eye. It is not a danger to vision until it starts 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 for the causes of pinguecula or pterygium is believed to be chronic exposure to ultraviolet light from the sun.
Bulging eyes can be part of a normal facial feature.
But when the eyes were not bulging and started to protrude forward, the clearest cause could be a problem with the thyroid gland and needs medical attention.
A single protruding eye can be caused by an injury, an infection, or, more rarely, a tumor behind the eye.
Swollen or fluttering eyelids
The eyelids can also indicate some diseases, mainly related to minor conditions of the eyelid glands.
A common condition is a chalazion or eye “stye” – as it is popularly known -, which appears as a red lump on the upper eyelid and, less often, the lower eyelid. It is caused by a blocked sebaceous gland.
It usually disappears on its own or with hot water compresses. If it persists, it needs to be removed with a simple procedure.
The tremor in the eyelids (ocular myokymia) can be caused by irritation or even heat. It often appears to be much worse than it really is.
In most cases, it is perfectly harmless and can also be related to stress, nutrient imbalance, or excessive caffeine consumption.
This article is a guide only. If there are doubts about your health, it is essential to seek a specialist.
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