What is Cataract. Risk factors, Complications, Signs and symptoms, Prevention


Cataract is the blurring of the eye lens which alters the ability of the eyes to focus light or well-defined image on the retina. In simple terms, Cataract is a disease which clouds the lens inside the eye, leading to a decrease in vision. Since they often develop slowly and without pain, lifestyle and vision can be adversely affected unnoticed by most people.  It shows that most people do not know that they have them at first. However, as the clouding progresses, vision impairment sets in and gradually gets worse.

Presently, there is no medical treatment to prevent the formation or progression of cataracts. It is the most common cause of blindness but can be conventionally managed and treated with glasses and surgery which are very effective and safe procedures.

The major causes of cataracts are aging, trauma and significant exposure to radiation.  Cataracts cause more vision problems globally than any other eye condition or disease. Cataract is visually debilitating and poses a high economic and health burden in terms of lost work hours and need for early surgical intervention for sight recovery. Most cataracts are very common in elderly people, stealing their vision after age 60 especially. Globally, cataracts are the primary cause of preventable blindness.  Therefore report your cataracts status today and sustain your vision tomorrow.


Cataract is the gradual opaque or plaque-like formation in the eye lens which affects focusing of light or an established object on the retina at the back of the eye where visual information is received and analyzed. Visual loss occurs because opacification of the lens obstructs light from passing and being focused on the retina. Cataract develops gradually and at maturity, it is called ripe cataract.  Over time, cataracts cause the deposition of yellowish-brown pigment within the lens and this combines with disruption of the normal architecture of the lens fibers to reduce transmission of light, which in turn leads to visual disorders.

Cataracts are not usually painful. Cataracts are not hazardous to the sufferer’s health or the general health of the eye(s). Cataracts do not usually cause any change in the appearance of the eyes.  If a cataract becomes hyper mature (completely white), it may need to be removed especially if there is inflammation or pain.


Apart from a wide variety of other causes, biological aging  (responsible for about 51% of cataracts related global blindness in both male and female) is the most common cause of cataracts. This aging factor commonly causes the eye lens proteins to denature and degrade over time. Other factors are trauma or eye injury that causes swelling, thickening and whitening of the lens fibers which may obstruct light from reaching the retina; and radiation from ultraviolet light and X-rays, plus electric and heat injuries from microwaves. Other things that promote cataract formation include genetic component abnormalities and syndromes, skin diseases such as atopic dermatitis and eczema. Cigarette smoking, frequent intake of excessive alcohol, diabetes mellitus, iodine deficiency and some medications immensely contribute to cataracts formation in the eye(s).


Those with cataracts commonly experience difficulty appreciating colours, driving especially at night, reading, recognizing faces and coping with glare from bright lights.  Patient’s long-distance vision is more severely attacked at first. Cataracts can occur in either or both eyes. If they develop in both eyes, one will be more severely affected than the other. It cannot spread from one eye to the other. The nature of cataracts in the eye may be partial or complete, stationary or progressive, hard or soft.


The main types of cataracts are age related and congenital (childhood cataracts). As aging sets in, any type or a combination of these three secondary types can develop during human life cycle. The three are Nuclear, Cortical and Posterior subcapsular cataracts.

Age related cataracts are the most common and appear later in life. They are caused primarily by the hardening and yellowing of the eye lens with time. Age related cataracts occur mostly in those who have smoked or had excessive exposure to ultraviolet light.

Congenital cataracts (childhood cataracts) may be present when the baby is born or immediately after birth. They occur when something alters the normal growth of the fetus. Children of mothers who take certain medications or contracted measles or rubella during pregnancy often suffer from cataracts.

Nuclear cataract forms in the centre of the lens and cause the gradual clouding of the nuclear or the central zone of the eye(s) to become yellow or brown. Cortical cataract is in form of white, wedge-shaped opacity and forms around the edges of the eye nucleus. This defect gradually moves in a spoke-like manner to the lens cortex which surrounds the central nucleus of the eye. It occurs when there are changes in the fluid contained in the periphery of the eye lens.   Posterior subcapsular cataract occurs as a result of degenerative lens fibres which have developed abnormally at the back of the eye lens and it progresses fastest. It begins as a minor sharply demarcated opaque or cloudy area on the posterior or back surface of the eye lens just beneath the lens capsule.


The main complications of cataracts are:

  • Falling
  • Depression
  • Blindness


Signs and symptoms of cataracts vary depending on the type of cataract, though there is considerable overlap. The most common signs and symptoms of cataracts are cloudy, blurry or misty vision, colours appearing faded or less clear, glare – vision are sometimes worse with lights from headlights, lamps or sunlight; halo may appear around bright objects such as car headlights or street lights and poor night vision. There may be double vision or multiple images in one eye (this symptom may clear as the cataract gets larger). People may observe frequent prescription changes in eyeglasses or contact lenses (eventually wearing of glasses may become less effective) and vision alterations by small spots or dots which blur parts of field of vision. Other signs and symptoms of cataract include vision getting worse when lights are dimmed, eyestrain, more frequent blinking in an attempt to clear vision, eye inflammation or pain and headache.


People should avoid direct and prolonged exposure or contact with injurious radiations, personal behaviour such as cigarette smoking, excessive alcohol use and habitual harmful rubbing or pressing of the eyes. Long-term exposure to bright sunlight and long-term use of corticosteroids should be avoided. Other things people should avoid to prevent and control cataract include trauma that could cause eye inflammation or injury and exposure to lead – lifetime exposure to lead can be hazardous and may increase the risk of developing cataracts. People should avoid the use of glasses which are not of the most accurate prescription possible, and taking of alpha-blockers (which may increase the difficulty of cataracts surgery) without medical advice.

Those at high risk like airline pilots, microwaves users, glass blowers and furnace workers should wear ultraviolet-protecting sunglasses. At age 60 or older, have a comprehensive dilated eye examination at least once every two years for signs of cataracts and other age-related vision problems. Be in regular contact with an eye care professional who should examine your eyes and be familiar with your medical history. Eat plenty of fruits and vegetables; whole grains, unrefined carbohydrates, good quality fats (avocado, olive oil, omega oils) and either plant proteins or lean animal proteins with antioxidants. Install brighter lighting gadgets in your apartment (Halogen lights may help a lot). Wear anti-glare sunglasses or magnifying lenses on sunny days and refrain from driving at night.

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