The eye is a crucial yet sensitive organ of our body, which is vulnerable to infections and diseases. A cataract is one such common eye condition and a potential cause of blindness among Indians. This article will comprehensively discuss cataracts, its types, symptoms, causes, diagnosis, treatment and prevention.

Read on to know these in detail.

A cataract is an eye condition where the lens turns cloudy or foggy. Such a condition disrupts the functionality of the eye lens, leading to blurry vision and, in worse cases, vision loss. Further, the change of vision depends on the location and size of the cataract.

Wondering how cataracts are formed? Keep reading.

A lens is located behind the iris, the coloured part of an eye. It focuses the light passing into the eyes and produces clear and sharp images on the retina, a light-sensitive eye membrane.

Due to age and medical conditions, the lenses lose flexibility and become thicker and eventually turn opaque. Further, proteins and fibres of the lens break down and assemble, forming cataracts. As the cataract develops, the lens becomes more opaque and scatters and blocks the light when passing through it, hampering visibility.

Nonetheless, cataracts commonly form in both eyes but not always simultaneously or at the same rate. Cataracts form at different positions in the lens and are categorised into several types.

Here are the 15 types of cataracts:

• Nuclear Cataract: This kind of cataract forms in the middle of the lens and turns the nucleus or centre yellow or brown. Under this condition, individuals have difficulty seeing small objects or letters, and halos form while looking at bright things at night or in the dark.
• Cortical Cataract: It is a wedge-shaped cataract that forms around the edges of the nucleus known as the cortex. As a cortical cataract develops, it scatters light.
• Posterior Subcapsular Cataract: This kind of cataract develops faster than the former ones and damages the back of the lens capsule. It interrupts the path of light, affecting the close-up vision.
• Anterior Subcapsular Cataract: It forms inside the front of a lens capsule and is often caused due to any injury or swelling in the eye.
• Congenital Cataract: This type of cataract is rare and found among newborn babies. Congenital cataracts happen if the mother suffers from rubella during pregnancy.
• Secondary Cataract: This is caused as a result of medication after-effects and diseases such as diabetes and glaucoma. A few steroids like prednisone are responsible for the same. Individuals can get secondary cataracts after cataract surgery as well.
• Traumatic Cataract: Traumatic cataracts are formed due to injuries in the eye such as burns, chemicals or splinters or getting hit in the eye by an object.
• Radiation Cataract: This kind of cataract is often a side effect of cancer radiation treatment. Moreover, over sun exposure without proper eye protection is likely to result in radiation cataracts.
• Zonular or Lamellar Cataract: Commonly found among younger children in both eyes, lamellar cataracts are genetic. They are fine white dots in the middle of the lens that may appear Y-shaped.
• Posterior Polar Cataract: This is another kind of genetic cataract that occurs on the back centre of the lens.
• Anterior Polar Cataracts: These cataracts do not disrupt visibility and develop on the front and nucleus of the lens and appear as tiny white dots.
• Post-vitrectomy Cataracts: This is a side effect of vitrectomy surgery that includes the removal of the clear gel from the eye centre.
• Christmas Tree Cataracts: Christmas tree or polychromatic cataracts form coloured and shiny crystals in lenses and are typical among individuals with myotonic dystrophy.
• Brunescent Cataracts: This is the advanced stage of nuclear cataract, and its surgery is intricate and involves complications.
• Diabetic Snowflake Cataract: The rarest among all types of cataracts, it is common among diabetic patients and appears as a grey-white pattern like a snowflake.

The prominent signs of cataracts are as follows:

• Blurry, cloudy or foggy vision
• Trouble of seeing objects that are close or near, especially among older people
• Poor night vision
• Increased sensitivity to glare
• Problem seeing colours
• Frequent changes in prescribed glasses or contact lenses
• Double vision in the affected eye

• The primary causes behind cataract formation are ageing and injuries damaging the lens tissues. These conditions lead to protein and fibre catabolism of the lens and cause cloudy or blurry vision.
• Inherited genetic complications trigger the chances of cataracts.
• Past eye surgery
• Other eye ailments
• Medications
• Diabetes
• Usage of steroids for a prolonged period

Individuals with the following conditions are at higher risk:

• Obesity
• Heavy consumption of alcohol
• Smoking
• Excessive exposure to sunlight
• High blood pressure
• Exposure to radiation like X-rays, cancer therapies etc.

After reviewing one's medical history, ophthalmologists or eye specialists recommend the following eye examinations to individuals exhibiting prominent symptoms of cataract.

• Visual acuity test
• Retinal test
• Applanation tonometry
• Slit-lamp test

The only treatment for cataracts is surgery. However, there are several types of operations available to treat cataracts. They are:

1. Small-incision Surgery

Also known as phacoemulsification, surgeons make a tiny incision on cornea in this operation. Then, they employ a small device inside an eye that generates ultrasound waves to break up a cataract. Lastly, they extract the pieces and place an artificial lens as a substitute.

2. Large-incision Surgery

Also known as extracapsular cataract extraction, this is chiefly prescribed if a cataract is larger in size or at an advanced stage. It includes extraction of an affected lens and replacing it with an artificial one.

3. Femtosecond Laser Surgery

This surgery involves a laser to break up a lens and replace it with a new one. Moreover, it is recommended for individuals with astigmatism, a curve on the cornea responsible for blurry vision. Surgeons equip lasers to reshape cornea and cure cataracts.

Though there are no recommended ways to prevent cataracts, adopting healthy lifestyle choices may lower the chances. A few of them are as follows:

a. Vitamins C and E-rich Diet

Antioxidants like Vitamins C and E possess properties that reduce the chances of cataract development. Individuals can include the following food items in their daily diet.

Vitamin C-rich Food Options

• Any citrus fruits like orange, grapefruits, lemon etc.
• Kiwifruit
• Tomatoes
• Green and red peppers and more

Vitamin E-rich Food Options

• Peanuts
• Spinach
• Almonds
• Broccoli
• Vegetable oils such as sunflower, wheat germ etc.

b. Quit Tobacco Consumption

Besides its long list of health hazards, smoking creates excess free radicals in the eyes that harm the cells, causing cataracts.

c. Restrict Alcohol Consumption

Though drinking standard portions of alcohol every day lowers the chances of cataracts, excessive consumption triggers the chances.

d. Protect Eyes Using Sunglasses

Sunglasses are the best way to keep the sun's harmful ultraviolet (UV) rays away from the eyes. Apart from skin issues, UV rays damage the protein of the lens, resulting in cataracts.

e. Control Blood Sugar Level

As diabetes is a potential cause of cataracts, it is wise to keep blood sugar levels in check. High blood sugar level for a prolonged period swells up the lens and converts blood sugar into sorbitol. The accumulation of sorbitol inside the lens forms cataracts.

Apart from these, regular eye check-up, especially for individuals between the age group 40 and 60, is essential to detect cataracts or any other complications at an early stage.