What are Cataracts?

A cataract can simply be referred to as a clouding or an opacity of the lens of the eyes. Normally, the lens of the eye is clear. The probability of developing cataracts gets higher with age.

How Cataracts Occur

The eye lens is transparent, elliptical in shape and sits just behind the pupil. Its function is to focus the light that gets in your eye through the pupil into images on the retina.

Among young people, the lens can change shape easily since they are still flexible and elastic, hence allowing the eyes to clearly focus on both close and distant objects.

However, as people age into their mid-forties, the lens harden and lose their elasticity due to some biochemical changes the lens cells undergo. The hardening of the lens leads to various eye problems such as presbyopia and long-sightedness, the reason you see most elderly people wearing glasses.

For cataracts to form, the proteins in the eye lens of some people get clumped together forming opaque, cloudy areas in the lens known as cataracts.

Depending on what causes the cataracts, they may either develop slowly over several years or rapidly over a short period of time.

Cataracts vary in density and can be located anywhere in the lens. When they block the passage of light to the retina, vision becomes cloudy.

Types of Cataracts


The lens has three parts or layers. The outermost one is called the capsule, the innermost one is the cortex and between them is the nucleus. These three areas are where cataract usually occurs. The following are the three types of cataract based from the areas affected:

  • Subcapsular cataract. This occurs beneath the capsule. It creates a foggy circle on the lens. People who are diabetic, extremely nearsighted, and who use steroids are prone to having this type of cataract.
  • Nuclear cataract. This cataract is the most common type that occurs due to aging. This causes hardening and yellowing of the lens.
  • Cortical cataract. This is the cloudiness that happens in the lens cortex. This cataract looks like white, steep triangles around the outer boundaries of the lens that point toward the center of the eye. People with diabetes are prone to this type of cataract.

Causes of cataracts

Old age is widely accepted as the major risk factor for cataracts. Nevertheless, scientists are still uncertain about the exact biological mechanisms that make aging cause the cells in the lens clump together. The following are some of the leading factors that researchers have brought forward:

Oxidants and Lack of Glutathione

Oxidants, also known as Oxygen-free radicals are particles that are naturally produced in your body during chemical processes. Production of Oxygen-free radicals is accelerated by smoking, toxins, infections, UV radiation among other factors.

When oxidants are in excess, they can have very adverse effects on body cells throughout the body. Cataracts is one such harmful effect that can be caused by overproduction of oxidants especially combined with the absence of a common anti-oxidant known as glutathione.

Glutathione is usually found in large amounts in the eyes, and helps counter the effect of free radicals.

Sunlight and Ultraviolet (UV) Radiation

Normal sunlight consist of UV radiation which is capable of penetrating several layers of the skin and cause damage to the cells. The eye lens is protected from the harmful UV radiation by the body’s structural features such as the eyelids, the nose, overhanging brows, eyelashes etc.

Over a long period of time, the UV exposure affects the lens causing changes to the pigments which contribute to the development of cataracts.

A part of the UV radiation from sunlight called UVB is also known to cause muscular degeneration and disorders of the retina that are age-related.

Some researchers are concerned that the growing global temperatures and damage to the ozone layer may increase the number of people with cataracts worldwide.

Radiation Treatments

Some common radiation treatments for treating different types of cancers are known to cause cataracts as some of the side effects.

Electromagnetic Waves

Researchers and scholars alike have raised questions about the effect of low radiation from computer screens. Up until now, there is no study linking the development of cataracts to screens, however, opticians suggest to sit at least a foot away from video display terminals.


Cataracts can be caused by a long-term use of oral steroids. Nasal-spray and inhaled steroids have shown conflicting results with regards to whether they can directly cause characters or not. Research about inhaled steroids is significant among medical practitioners since it is a common treatment for asthma and allergies.

Causes of cataracts in children

In very rare occasions, a child out of 10,000 births is born with cataracts. A condition known as congenital cataracts. Congenital cataracts are associated with genetic disorders. They are usually as a result of inborn abnormalities in the shape of the lens or the capsule.

In addition to this, an infection during child delivery can also lead to cataracts especially if the mother abuses alcohol or other types of drugs.

Symptoms of Cataracts

Cataracts have little effect on vision during the early stages. As the cataracts develop, mostly with age, the following symptoms may occur:

  • Double vision, cloudy vision, or both may occur as the initial signs.
  • Yellowish tint on images reaching the retina due to the reduction of color vibrancy
  • Increased sensitivity to bright lights making it hard to drive at night due to glare.

Symptoms may be different depending on where the cataracts occur. Additionally, highly developed cataracts, the pupil will look milky instead of its usual black and vision can be reduced to the discernment of just either dark or light.

Treatment of Cataracts

Currently, surgery is the only and most common treatment for cataracts. However, rarely does cataracts cause an emergency medical situation. Most cataracts only reduce the ability of a person to see clearly as they used to meaning surgery is often delayed for a long period of time. In addition, cataracts can be managed in its early stages in the following ways:

  • Contact lenses or glasses with strong lenses
  • Use of magnifying glasses while reading, or even regular reading glasses.
  • Strong lighting
  • Dilating the pupils using medication for people with capsular cataracts, however, this treatment does not stop the glare caused by cataracts.

Normally, patients and their families have a lot of time to go over the options available to treat or manage cataracts and discuss it with their opticians and ophthalmologists. Cataracts are not known to progress in any specific rate but progression varies from patient to patient.

The lens is a very important part of a camera. It regulates the right amount of light that goes into it to produce amazing pictures.

But what if it’s fogged up?

The light won’t get in and the photos produced will be murky and indiscernible. Just like the camera lens, the human eyes will not be able to see if their lenses are clouded. When this happens, the eyes are known to have cataracts.

Cataract is an eye disease which involves clouding of the eye because of abnormal development of protein on the lens obstructing light from successfully passing through. The lens is a part of the eye placed between the colored part called the iris and the innermost light-sensitive tissue layer called the retina. Its role is to focus light to the latter.

Cataract is usually associated for visual impairment or vision loss.

What are causes of cataracs?

Cataract can be age-related but the cause is still unknown. Cataract can be found in babies as well. A baby is born with cataract as a result of trauma, infection or underdevelopment before birth. Cataract can also develop later in childhood. Secondary cataract can be developed as a complication to other medical conditions such as diabetes and obesity.

It can also be caused by frequent exposure to ultraviolet rays, radiation, and prolonged use of certain substances and drugs like steroids. Traumatic cataract is formed due to eye injury, inflammation, or even surgery.

What are the signs and symptoms of cataracts?

It may start unnoticed, but over time, patient’s vision will begin to blur a little. Light from the sun, lamp or other light sources may begin to become a little too bright or intense.

Colors may not be as vivid and may seem faded. Nuclear cataract in its early development will give the patient a “second sight” or a vision improvement but only temporarily as the cataract will become more profound.

A patient of subcapsular cataract will not be able to determine any symptom until the cloudiness fully develops.

How are cataracts treated?

Cataracts are treated through surgery. But patients can also use glasses, contact lenses, bifocals and other vision aids.

Patients who undergo surgery will have their affected lens removed and mostly replaced with an artificial lens called intraocular lens (IOL).