Causes of cataracts What causes cataracts

This? Cataract is a very common eye disease nowadays, the disease causes a high rate of blindness, and there are many elderly people with this disease now, so, what? Let's take a look.

Experts tell us that there is a tissue in the human eye called the lens, which is normally transparent, and light rays reach the retina through it and some refractive interstitium, so that people can see the external objects clearly. When the lens in the eyeball becomes cloudy and changes from transparent to opaque for some reason, preventing light from entering the eye and reaching the retina, vision will be affected, making people unable to see clearly, and cataract occurs. Any cause of the opacity of the lens is called cataract, because the lens itself has no blood** and depends on aqueous humor and vitreous penetration; Cataracts, on the other hand, are most common in older people.

Due to the aging process of human beings, the nutrition, digestion and absorption functions of the human body and the metabolic function of the body are gradually reduced, resulting in poor lens nutrition and lens tissue degeneration. Of course, the pathogenesis of senile cataract is still not fully understood, so many people believe that it is caused by hardening and dehydration of lens fibers. In other words, when the human body is aging, the lens fibers gradually harden, the nucleus shrinks and the equatorial cortex is stretched by the suspensory ligament, so that there are cracks between the peripheral lens fibers, causing the lens to become cloudy.

It may also be due to an increase in the osmotic pressure of the aqueous humor due to aging, which can dehydrate the lens and become cloudy. The course of senile cataract can generally be divided into four stages: initial stage, immature stage, mature stage, and overmature stage.

Cataracts are initially unaware of vision loss and blurred vision, and as the disease progresses, it may only be possible to see the hand shaking in front of the eyes or only the sense of light. Some cataract patients also show symptoms such as myopia, monocular diplopia or polyopia, fixed dark shadow or dark vision in front of the eyes, loss of color brightness, and photophobia, glare. At first, the ocular opacity (i.e. in the area commonly known as the dark eye) is relatively mild or small, and then gradually worsens to the point that it significantly affects vision and even blindness.

A: The main causes are aging, aging of human organs, prolonged exposure to strong light and ultraviolet radiation, degeneration of the capsule cortical layer, and certain diseases and genetics. Among them, the aging of human organs is the main cause, so cataract patients are mostly elderly.

Cataract disease: 1. Cataract in the elderly: it has a lot to do with the grade, with the increase of age, the permeability of the lens capsule increases, and the excessive accumulation of water in the lens denatures the lens protein, resulting in the turbidity of the lens; 2. Metabolic cataract:

Cataract caused by systemic metabolic diseases, such as diabetes, galactosaemia, Wilson's disease, parathyroid dysfunction; 3. Concurrent cataract: the main cause is eye diseases, such as uveitis, glaucoma, etc.; 4. Congenital cataract: the cause is rubella virus infection during embryonic development, etc., which needs to be done as soon as possible to avoid affecting the patient's visual development.

A cataract is a degenerative change in the transparency of the lens, or a change in color, resulting in a decrease in the patient's vision. The pathogenesis of cataract is complex and is the result of the long-term effects of various factors in vitro and outside on the lens.

Cataracts can be caused by any factor that affects the intraocular environment, and the most common causes include aging, genetics, metabolic abnormalities, trauma, radiation, poisoning, local nutritional disorders, and certain systemic metabolic or immune diseases, all of which can directly or indirectly damage the tissue structure of the lens and interfere with its normal metabolism, resulting in lens opacity. Epidemiological studies have shown that ultraviolet radiation, diabetes, hypertension, cardiovascular disease, etc. are all associated with cataract formation. There are many reasons why cataracts can occur, including the following:

Age: It is the most common cause of cataracts, and as we age, the lens becomes cloudy due to aging. Innate factors:

A cataract caused by genetic factors at birth is called congenital cataract. Pharmacological factors: such as long-term use of glucocorticoids or mydriatic eye drops, can lead to cataracts.

Ocular organic diseases**: e.g. retinitis pigmentosa, cataracts caused by high myopia. Traumatic factors:

Trauma can cause damage to the lens, which can lead to degeneration of lens proteins, which can lead to cataracts. Radiation factors: Long-term exposure to ultraviolet rays or other radiation rays can lead to degeneration of lens proteins, resulting in cataracts.

Causes of cataracts:

Cataracts are divided into congenital cataracts and acquired cataracts. Aging, genetics, local nutritional disorders, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can all cause lens metabolism disorders, resulting in lens protein denaturation and clouding, resulting in cataracts.

The most common cause is age-related cataracts. It is more common in middle-aged and elderly people over 50 years old, and the incidence tends to increase with age.

The lens of the eye is like a transparent glass bead, and when the lens becomes cloudy, the outside light entering the eye will be affected, resulting in blurred vision.

1. Causes of diabetes: Diabetic patients can lead to retinopathy and eye diseases. Therefore, diabetic patients must actively control their blood sugar, and if complications occur, they must be timely**, such as cataract surgery**.

In your daily diet, you should control the amount of small meals you eat. It can be based on coarse grains, such as wheat, buckwheat, oats, etc. Be careful not to eat greasy foods.

2. Age: The incidence of cataract is relatively high in the elderly, which can cause vision loss or blindness. Due to the opacity of the lens, cataract will only be caused by the opacity of the lens, there is currently no effective drug to **cataract, if it affects life, surgery can be considered**.

3. Environmental reasons: We are also exposed to some harmful substances in our lives, such as radiation, hormone drugs or trauma, which also cause cataracts. There is also a lot of exposure to sunlight is related, the lens is exposed to strong light for too long, it will cause the denaturation of crystal proteins, so it causes cataracts, we must pay attention to diet and rest in our daily life.

1. Radiation. If people's eyes are exposed to sunlight radiation for a long time, the incidence of cataracts will also increase, especially in highland areas, where sunlight radiation is more. This is mainly because the eyes are exposed to sunlight for a long time and are exposed to ultraviolet rays, and the lens undergoes redox processes, resulting in protein denaturation and turbidity, which induces cataracts.

2. Heredity. Congenital cataracts are present around the time of birth and are often associated with hereditary disorders. At the same time, it is divided into two categories: exogenous and endogenous.

Endogeneity is related to systemic lesions of the mother or fetus and causes damage to the lens, while exogeneity is mainly related to the development of the baby.

3. Endocrine disorders.

Endocrine disorders are also the cause of cataracts, and diabetics are more likely to develop cataracts than normal people.

4. Hypoxia. When the patient is in a state of hypoxia for a long time, the calcium, sodium and other elements in the lens will increase, and the content of vitamin C and potassium will decrease, resulting in an increase in the content of lactic acid, and finally cataracts.

5. Trauma. If you have had a traumatic injury to the eye, such as blunt force trauma, a stab wound or a car accident, the lens capsule ruptures, edema develops, and cataracts can occur.

6. Age. With the increase of age, the elderly gradually weaken all aspects of physical functions, lens function is also weakened, and the incidence of cataract increases.

Cataracts are an aging phenomenon of the eye. It can even be said that as long as you live long enough, everyone will get cataracts. Cataract is a well-known disease among middle-aged and elderly people, but many people do not know much about cataract.

The following is an introduction to what causes cataracts.

What causes cataracts

1.Ultraviolet rays

It is one of the leading causes of cataract, and the incidence of cataract has increased greatly in places such as plateaus where ultraviolet radiation is relatively strong, and the age of onset is early, such as plateau areas such as Xidai in China.

.Senile cataracts

Senile cataract is a phenomenon of aging. As we age, the lens in the eye slowly hardens and becomes cloudy, causing visual impairment. Symptoms include foggy vision, color vision changes, dark spots in front of the eyes, and diplopia.

3.Medications

Long-term use of steroidal drugs is the cause of this type of cataract. Some cataracts can be recovered as long as steroids are stopped, but most patients will have some residual lens opacity that cannot be recovered once cataracts occur.

4.Diabetes

When the blood sugar of diabetic patients rises, more glucose in the blood will enter the lens, which will eventually absorb water and swell and become cloudy, causing cataracts to occur. Nowadays, the incidence of diabetes in middle-aged and elderly friends is very high, and it is necessary to alert the possibility of cataract and fundus hemorrhage.

5.Trauma

Traumatic cataract is called traumatic cataract caused by traumatic injuries such as being stabbed in the eye by a sharp object or being hit by an object, resulting in damage to the lens and clouding. Depending on the severity of the injury, surgery may be performed**.

6.Congenital cataracts

It is more common in newborn babies because of chromosomal compilation, genetic factors, or intra-fetal infection. Soon after birth, white or gray cloudy dots appear on the eyes.

7.Concurrent cataracts

Intraocular disease causes the lens to become cloudy. Due to inflammation or degeneration of the eye, the lens is impaired in nutrition or metabolism, resulting in cloudiness. Common in uveitis, retinitis pigmentosa, and retinal detachment.

1.Congenital cataract, also known as developmental cataract, mostly exists before and after birth, mostly quiescent, can be accompanied by hereditary diseases, there are two categories: endogenous and exogenous, endogenous and fetal development disorders, exogenous is caused by damage to the lens caused by systemic lesions of the mother or fetus, congenital cataract is divided into anterior cataract, posterior cataract, circumnuclear cataract and total cataract.

2.Acquired cataract after birth due to systemic diseases or local eye diseases, abnormal nutritional metabolism, poisoning, degeneration and trauma caused by lens opacity, divided into 6 types:

Senile cataract, the most common, also known as age-related cataract, is more common in people over 40 years old, and increases with age, and is related to many factors, such as the slow metabolism of the elderly is related to degenerative changes, and some people believe that it is related to long-term sunlight exposure, endocrine disorders, metabolic disorders and other factors, according to the location of the initial opacity can be divided into two categories: nuclear and cortical.

Concurrent cataract (complicated by other eye diseases).

Traumatic cataracts.

Metabolic cataracts.

Radiation cataracts.

Drugs and toxic cataracts.

Generally, only surgery can **cataract**, if you have similar symptoms, it is recommended that you go to the hospital in time**.

According to Wang Yiru, an expert from the cataract group of the Eye Hospital of Henan University Eye Center, cataract can be divided into developmental, senile, concurrent, traumatic, toxic, metabolic disorder, corticosteroid and posterior according to its causes.

Developmental cataract, also known as congenital cataract, has two types: endogenous and exogenous, and the endogenous cause is related to fetal development disorders and is hereditary.

Exogenous causes refer to the damage to the lens caused by systemic lesions of the mother or fetus, such as viral infections such as rubella, measles, chickenpox, mumps, parathyroid insufficiency, malnutrition, and vitamin deficiencies in the first month of pregnancy.

The formation of senile cataract is mainly the denaturation of protein, the increase of insoluble protein, sodium and calcium, etc., while the decrease of potassium and vitamins and the absence of glutathione, 85 of the lens protein is water-soluble albumin, water-soluble albumin can be converted into insoluble protein, the older the age, the more insoluble protein content.

In addition, vitamin deficiency, changes in crystal pH value and some toxic substances infiltrating into the crystal can cause the denaturation of crystal protein, resulting in turbidity, oxidative damage to senile cataract is the initial factor of cataract formation, cataract formation risk factors include excessive drinking, excessive smoking, excessive childbirth in women, some systemic diseases, etc., but so far the cause of senile cataract has not been fully clarified, and it remains to be studied.

Concurrent cataracts are clouding of the lens caused by certain eye diseases themselves. Eye diseases such as iridocyclitis, choroiditis, retinal detachment, retinitis pigmentosa, glaucoma, high myopia, purulent corneal ulcer, and old eye trauma can cause concurrent cataracts. Traumatic cataracts include mechanical, radiation, and electric shock.

Diabetic cataract is more common in metabolic cataract clinically. Corticosteroid cataract is caused by long-term heavy use of corticosteroids in the eye or systemically. Posterior cataract refers to the clouding of the remaining cortex and capsule after cataract extracapsular extraction or linear extraction.