cataract summary

Cataracts, macular degeneration and glaucoma are the three main eye diseases that occur with aging and can cause blindness.

Cataracts have been described since antiquity. The blurred vision due to cataracts is an allusion to the vision that the person would have if they were looking through a waterfall, “cataract” in Latin means “waterfall”.

Cataracts affect the lens of the eye. Like an optical lens, the lens allows vision to adapt, focusing the image by changing its shape (contraction or elongation). This is exactly the same physical principle used in cameras or telescopes, for example.

With aging, the lens becomes cloudy and vision becomes blurred. It is a degenerative but progressive disease. Cataract is a senile disease (due to age). Other causes of cataracts exist, such as traumatic cataracts (due to an accident) or secondary cataracts (due to certain medications).

The mechanism of lens aging is not fully understood, but it appears to be due to free radical attack. To prevent this situation, a diet rich in antioxidants would be welcome, so it is recommended to eat fruits and vegetables regularly.

The main treatment for cataracts is surgery.


Cataract means “waterfall”. Cataracts are an eye condition characterized by increasingly blurred vision, as if looking through a waterfall.

There are several types of cataracts, depending on the cause of the disease: senile cataracts, traumatic cataracts and secondary cataracts.

senile cataract

Mostly, cataracts occur due to age, with clouding and hardening of the lens. The lens is a lens positioned behind the iris and acts as an optical lens used in image formation by changing its shape. With aging, the lens becomes less flexible. It can no longer so easily change its shape, and so the vision is disturbed. The aging process of the lens is not yet known, but it seems that this is due to the attack of free radicals, which represents the normal aging of the human body. This process is progressive. Senile cataracts become a nuisance after the age of 70, in general.

There are forms of juvenile cataracts, but this is rare. Children can be born with cataracts, but this is rather a cataract secondary to diseases contracted during pregnancy such as rubella, syphilis, genital herpes, or toxoplasmosis. Note also a genetic factor for cataracts. The latter effect can occur in children with Down syndrome.

traumatic cataract

Traumatic cataracts most often occur in people whose eye has been affected by traumatic injury, up to the point where the lens was hit. This is particularly the case for eye surgery, eye damage, blows to the eye, burns, chemical or physical, for example.

secondary cataract

Secondary cataracts are caused by the use of certain medications, such as cortisone. It can also be secondary to diseases such as poorly controlled diabetes, myopia, glaucoma, retinal detachment or uveitis.


– Worldwide, about 20 million people are affected by cataracts (WHO estimate in 2010). The WHO estimates that about 48% of blindness worldwide is caused by cataracts. These cases of blindness are, however, reversible by surgery.

– In the United States, nearly 4 million Americans underwent cataract surgery in 2017, according to CBSNews media .

– In France, it is estimated that 600,000 cataract surgeries are performed per year, while this disorder affects more than 20% of the population over 65 years of age.

– About 1 newborn in every 250 suffers from congenital cataracts.

– Women are the most affected by cataracts, according to the American institution National Eye Institute (National Institute of Vision). It is possible that the decrease in estrogen levels at menopause is partly responsible for the increased risk of cataracts in women.

According to the American magazine Prevention , from the age of 75, about half of Americans suffered from cataracts in 2018.


There are many causes of cataracts: age, illness, medications and trauma.


Cataracts mostly occur due to old age – it is called senile cataract. With aging, the lens hardens and becomes cloudy.

Unyielding, the lens can no longer play its part in deforming itself to create the image in the eye.

In fact, the lens is small, flexible and transparent, and allows light rays to enter the eye, where light information is converted into nerve impulses and transmitted to the brain through the optic nerve. The nervous impulse is “decoded” by the brain and forms the image. With hardening and clouding of the lens, the image seen, year after year, becomes increasingly faint and can cause blindness if left untreated.

The mechanism by which the lens becomes opaque and rigid is not well known. It seems that, with the action of free radicals present in the human body, it causes alteration of the lens proteins. These proteins are also altered when the eye is exposed to UV light, including UVB.


Diseases that can cause cataracts include diabetes when poorly controlled, eye conditions such as uveitis, myopia, glaucoma and retinal detachment.

Some diseases contracted during pregnancy and transmitted to the fetus can also cause cataracts in newborns. These diseases include toxoplasmosis , rubella , syphilis and genital herpes .

Cataracts can also be congenital, causing cataracts to occur in young children. This is particularly the case for people with Down syndrome.


Drugs that can cause cataracts to occur include long-term use of corticosteroids, either by mouth or by skin (cream, ointment). It all depends on the amount absorbed.


Any trauma that affects the eye and lens can put you at risk of developing major cataracts. So, wounds, cuts, blows to the eye can cause cataracts. Other injuries such as chemical or physical burns can also be the cause of a cataract.

Groups of risk

Cataract is a disease that occurs mainly due to the natural aging of the crystalline lens. Thus, all people are at risk of developing cataracts. Cataracts usually start in people over 65. Since this is a progressive disease, slowly the quality of vision is disturbed, because the lens is not completely opaque. At the age of 75, people really experience impaired vision.

Gender has no influence on whether or not a cataract occurs. Thus, men and women are equally affected by cataracts. Cataracts usually affect one eye more than the other.

While aging is the main risk factor for developing cataracts, there are aggravating factors. In fact, diseases such as diabetes , glaucoma , uveitis can increase the risk of cataracts. Drugs such as cortisone also increase the occurrence of cataracts. Exposure to UV rays, including solar UVB, increases the risk of cataracts. Thus, people who live around the equator are more prone to cataracts. Finally, everyone who has had injuries or trauma to the eye is more likely to develop cataracts.

In children, the risk of cataracts is much lower. But it does exist and this risk is greater in children with Down syndrome and children whose mothers contracted diseases such as rubella , syphilis , genital herpes or toxoplasmosis during pregnancy.

As seen in Epidemiology above, women are more affected than men by cataracts.


Cataracts are a painless condition, but they can become very unpleasant over time. First, cataracts cause a decrease in visual acuity and can cause subsequent vision loss. In early cataracts, no symptoms were observed. But with the passage of time, vision disorder and long blindness occur.

The following symptoms are characteristic of cataracts:

– Sensation of a veil before the eyes, sensation of looking through a waterfall.

– Blurred, blurred vision.

– Double vision.

– Darkening of vision (rays of light have difficulty reaching the optic nerve).

– Difficulty walking or driving at night.

– Decreased color perception. They become dull, less vibrant.

– Excess glare, especially in the presence of strong light (photophobia symptom this is already rare).

 – Accelerated increase in myopia. Frequent changes of glasses, contact lenses. So, logically, vision improves temporarily, but with the increase of cataracts, vision also starts to bother.

 – Vision of distant objects is the first to be disturbed.

 – The disturbance of vision is not uniform and can occur more on one side than on the other. Although cataracts are bilateral, they are more pronounced in one eye.

Cataract symptoms appear progressively, with mild symptoms at first, then increasingly intense as the disease develops.


Cataract is a painless disease and therefore it is rare to notice the symptoms. Thus, cataracts are basically detected during routine examination by the ophthalmologist. It is important for those suffering from decreased visual acuity to consult an ophthalmologist to detect the disease quickly. Cataracts are not reversible, but they can be treated safely.

The ophthalmologist may suspect a cataract by identifying characteristic symptoms of the disease. It is essentially a clinical diagnosis.

In the routine eye consultation, the ophthalmologist will use a slit lamp. It is a kind of microscope with which the doctor can light the eye and inspect each part to detect diseases. As for cataracts, the eye doctor will pay special attention to the lens, identifying its shape, size and color (its transparency, reflection).

To make a quantitative analysis of reduced visual acuity, the ophthalmologist will use the Monoyer and Parinaud scales.

Note that advanced cataracts cause clouding of the lens, which is visible to the naked eye. In fact, the pupil becomes whitish gray. When the crystalline lens is still not completely opaque and whitish, the ophthalmologist will use solutions to dilate the pupil and see what it looks like.


Cataract is a disease that does not hurt, but its aggravation causes a significant decrease in visual acuity. This decrease can even cause blindness.

Even painless, it is important to detect and treat cases of cataract early, because in developing countries cataract accounts for more than a third of all blindness. This is partly explained by malnutrition and excess UVB rays. Treating cataracts can prevent many cases of blindness.

Developed countries are not left behind. The elderly are more numerous, and cataracts are very common. In this case, access to the doctor is facilitated and patients are seen more quickly.

Because of decreased visual acuity, in addition to blindness, again, the quality of life of patients is impaired. Including simple activities such as reading and driving.

A characteristic sign of an advanced cataract is the color of the pupil. The pupil becomes whitish or grayish. As a result, the lens is no longer transparent to the naked eye.


There is no drug treatment for cataracts, either in the form of eye drops or pills to swallow. The only treatment for cataracts is surgery.

Surgery is performed on patients whose eyesight is impaired and impairs normal activities like reading, driving, etc. In fact, when the cataract is not too severe and daily activities can still be done without too much difficulty, there are some simple steps to improve vision:

– The ophthalmologist can prescribe suitable glasses or contact lenses to rehabilitate vision.

– Wear safety goggles, due to the sensitivity that the glare can cause.

– Adequate lighting is necessary at home: cataracts can cause darkening of vision.

– Eat plenty of vegetables and fruit, in order to have a sufficient amount of antioxidants and thus neutralize free radicals, responsible for the aging of the crystalline lens. Examples of antioxidants are vitamin C , vitamin E , beta carotene and lutein.

the cataract surgery

When the cataract is already well advanced, the solution is surgery. The latter consists of extracting the lens nucleus under anesthesia. The surgeon holds the lens envelope (called a capsule) in place, removes the nucleus with ultrasonic sputtering (easier to remove), and replaces it with a new artificial lens (a lens).

There are two types of lenses. Rigid lenses and soft lenses. Rigid lenses require a larger corneal opening (5.5 mm). These lenses have been used a lot. Soft lenses, however, allow for a much narrower aperture because the lens is folded and inserted like an envelope. The type of lens used depends on the patient. In fact, lenses can also correct vision if the person is nearsighted, has farsightedness, astigmatism or presbyopia.

This process is painless and performed very quickly. There is no need for hospitalization. However, for safety reasons, the operation is performed on each eye separately. The surgeon starts with one eye and a few weeks later operates on the other eye. Vision returns very quickly within a few days to a few weeks (3 weeks in general). Surgical treatment is well known and mastered nowadays.

The main complication lies in the fact that the lens left in place can also cause cataracts and thickening. In this case, however, never as serious as in the first. Also, a simple laser correction can restore good vision.

For some patients suffering from other eye problems it is not possible to replace the lens with an artificial lens. After removing the lens, patients must wear special glasses or contact lenses.

Benefits of cataract surgery (studies) 

Increased life expectancy among women after cataract surgery
Older women who have had cataract surgery are living longer than those who have not had cataract surgery and have the disease, according to a study published in 2017. In detail, this study took more than 74,000 women aged 65 years and older with cataracts and showed that this eye surgery is associated with a 60% reduction in the risk of all-cause mortality. Researchers, however, still don’t know the exact causes behind this longer life expectancy. One hypothesis is an improvement in the quality of life of these women, thanks to better vision resulting from the operation. This study was published online October 26, 2017 in the scientific journal JAMA Ophthalmology (DOI: 10.1001/jamaophthalmol.2017.4512).

– One study found an association between cataract removal and reduced risk of dementia (eg Alzheimer’s). This study was published online December 6, 2021 in JAMA Internal Medicine (DOI: 10.1001/jamainternmed.2021.6990 ). To reach this conclusion, researchers followed more than 3,000 elderly people without dementia (who had cataracts or glaucoma) for approximately 24 years.1🇧🇷 During the study period, the risk of developing dementia was 29% lower in people who had a cataract extraction compared to people who did not have cataracts removed. It is important to note that the risk of dementia did not change in people who did or did not have glaucoma surgery, this operation does not restore vision. This study was observational and does not provide conclusive evidence that cataract removal protects cognition, ie, actually prevents dementia. However, the researchers note that some evidence shows that impaired senses (such as poor eyesight) contribute to social isolation and reduced brain stimulation, which are risk factors for developing dementia such as Alzheimer’s disease. Other factors, such as a decrease in the practice of physical exercises,

Tips & Prevention

– Cataract and replacement of the lens with a lens is a frequently used, well-known and controlled method. It is important for people to realize the healing will not be complete until after a month.

– Unpleasant symptoms may occur such as “an explosion of colors” after the operation. But it decreases with time. This sensation is due to the fact that the brain has adapted to the diminished vision in cataracts and amplifies the signals. It is a compensation of the brain.

– Once the lens has been replaced, vision returns to normal, but the signals are amplified, hence the unpleasant sensation of seeing bright colors. This can be very painful at times. This feeling will disappear with time.

– Even if the lens is replaced with a new lens, the surgeon leaves the envelope (also called capsule) in place most of the time. This envelope over time can also become opaque, causing a second cataract. The latter, however, is easy to treat with a laser.

– Although cataract surgery is known and well understood, it is essential that the patient uses eye drops correctly before and after the operation. This will not only facilitate the surgery itself, but also prevent infections.

– Stop smoking, this is a risk factor for cataracts.

Jeanne Kenney
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I’m a stylist trainer, a content creator, and an entrepreneur passion. Virgo sign and Pisces ascendant, I move easily between my dreams, the crazy world I want, and my feet on the ground to carry out my projects.

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