What is a Cataract?
In a standard eye, the natural lens is entirely clear. In an eye affected by cataract, the lens gradually becomes cloudy, preventing light from passing through properly to the retina. As clouding worsens, less light can pass through the lens, making it increasingly difficult to see clearly.
A cataract in the eyes develops slowly over a period of time. In the early stages, it may not cause noticeable vision problems. However, as it progresses, symptoms become more apparent and can begin to interfere with everyday activities such as reading, driving, watching television, or recognising faces.
How Common is Cataract in India?
Cataract is extremely common in India and remains a major reason behind avoidable blindness in the country.
According to PMC survey, cataract accounts for 66.2% of blindness cases among Indians aged 50 years and older. While the overall prevalence of blindness in this age group is estimated at 2%, untreated cataract account for the majority of these cases.
Elderly people are not the only ones affected by cataract. Studies have also reported that the prevalence of cataract is rising among people below the age of 60 years. Nearly 35% of people in the presenile age group show signs of the condition.
What are the Types of Cataract?
Medical professionals classify cataract based on two primary factors: where the cloudiness develops in the eye lens and what caused the condition. Here's an overview of some of the most common types.
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Nuclear Cataract This cataract develops in the nucleus (the central part) of the eye's lens. It occurs when the lens centre becomes denser and less transparent over time due to normal ageing. Occasionally, the lens may also show a yellowish or brownish tint.
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Cortical Cataract This type affects the cortex, i.e., the outer layer of the lens that surrounds the nucleus. It usually begins with cloudy, wedge-shaped streaks along the lens border and slowly spreads inward.
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Posterior Subcapsular Cataract Under this category, a cataract forms at the back of the lens, just beneath the thin capsule that surrounds it. Unlike some other types, it often develops relatively quickly.
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Traumatic Cataract A traumatic cataract is the clouding of the lens of the eye caused by injury. It can either happen right after the injury or appear months or even years later.
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Paediatric and Congenital Cataract It can be present at birth or develop during early childhood. Some newborns already have cataract at birth (congenital cataract), while some develop them during their childhood (paediatric cataract). They may be correlated with genetic conditions, infections during pregnancy, certain childhood illnesses, or eye injuries.
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Secondary Cataract This can happen following a cataract surgery and is also known as 'after cataract'. It happens when the membrane behind the artificial lens becomes cloudy, giving the appearance of a cataract. It is common but not a new cataract and can usually be treated easily.
What are the Symptoms of a Cataract?
While vision loss is the most common symptom across all types of cataract, each type has distinctive features. Let's take a look at the symptoms of various types.
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Symptoms of Nuclear Cataract
- Slowly worsening of vision over time
- Blurry or fuzzy vision, especially when looking at distant objects
- Hard to read or do close work
- The colours might seem dull, faded or yellowish
- Limited visibility when the light is low
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Symptoms of Cortical Cataract
- Increased sensitivity to glare, especially from headlights at night
- Blurred or double vision
- Halos around lights
- Reduced sharpness of both near and distant vision
- Trouble identifying different colours clearly
- Less contrast, objects less distinct
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Symptoms of Posterior Subcapsular Cataract
- Rapid decline in vision compared to other cataract types
- Difficulty seeing in bright sunlight or brightly lit environments
- Increased glare from lights
- Blurred or cloudy vision
- Double vision in one eye
- Halos around lights
- Near vision may be affected more than distance vision
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Symptoms of Traumatic Cataract
- Sudden or gradual reduction in vision following an eye injury
- Cloudy or blurred vision
- Visible cloudy or milky appearance in part of the eye
- Eye pain or discomfort
- Swelling around the affected eye
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Symptoms of Paediatric Cataract
- Reduced response to light or visual stimulation in babies
- Difficulty recognising faces, objects, or toys
- Misalignment of the eyes (strabismus)
- Unusual eye movements
- Sensitivity to bright light
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Symptoms of Secondary Cataract
- Gradually worsening vision after cataract surgery
- Recurrence of cataract symptoms, like blurred, cloudy, or hazy vision and having difficulty seeing clearly at both near and far distances.
What Causes Cataract?
Cataract primarily develops due to changes inside the eye lens. Some common causes and contributing factors include:
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Ageing: Age is the most common cause of cataract worldwide. As people grow older, natural changes in the lens can make it thicker, less flexible, and progressively cloudier.
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Breakdown of Lens Proteins: The lens contains proteins that are normally arranged to keep it clear. Over time, these proteins can deteriorate and clump, forming cloudy patches that impair vision.
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Eye Injuries: Major injuries to the eye can impair the lens and lead to cataract formation either immediately after the injury or many years later.
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Previous Eye Surgery: Some people may develop cataract following certain eye procedures due to changes that occur in the eye after surgery.
Risk Factors of Cataract
Although anyone can develop cataract, certain factors increase the risk of cataract or cause it to develop earlier in life. Some of them are mentioned below:
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Long-Term Use of Steroid Medicines: Excessive use of corticosteroids for a long time can increase the risk of cataract, especially when taken in high doses or over extended periods.
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Excessive Exposure to Sunlight: Spending long periods in the sun without proper eye protection may increase the risk of cataracts due to exposure to ultraviolet (UV) radiation.
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Smoking: Those who smoke or consume tobacco have a higher risk of cataract development and may contribute to earlier onset of the condition.
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Radiation Exposure: Exposure to radiation, particularly during certain medical treatments, can increase the likelihood of cataract formation.
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Genetic Factors and Family History: Some people inherit a greater tendency to develop cataract. Certain genetic conditions can also increase the risk of cataract occurring at a younger age.
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Diabetes and Other Medical Conditions: Certain health conditions, particularly diabetes, can increase the risk of developing cataract and may cause them to appear at a younger age.
What are the Complications of Cataract?
If left untreated, cataract can worsen over time, damage vision, and increase the risk of several serious eye conditions. Also, due to cataract correction surgery, some complications do occur.
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Severe Vision Loss: As the cataract progresses, patients experience significant vision impairment. It affects your regular tasks like reading, driving, and recognising faces.
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Blindness: If the lens becomes completely opaque, vision may be lost altogether. As age-related cataract develop slowly, complete vision loss happens only if the cataract is left untreated for years. However, in other cataract types, vision may be lost more rapidly.
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Corneal Edema: The cornea, i.e., the outermost layer of your eye, may get swollen after cataract surgery. This can cause blurred vision, blisters, light sensitivity, and pain.
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Complications Due to Eye Trauma: Eye injuries can sometimes cause traumatic cataract, which may develop immediately after the injury or appear weeks, months, or even years later. In severe cases, traumatic cataract may progress rapidly and increase the chance of permanent vision loss if not treated promptly.
When Should I See My Healthcare Provider?
See a doctor if you notice any changes in your vision, no matter how minor the issue seems. Cataract often develops slowly, so it can be easy to miss the symptoms until they begin to interfere with your daily activities. If you have experienced blurred vision, difficulty seeing at night, increased sensitivity to light, or changes in how you see colours, you should schedule an eye exam.
People who have risk factors like older age, diabetes, family history of cataract, long-term steroid use or previous eye injuries should not ignore any changes in their eyesight and must get regular eye check-ups done.
How is a Cataract Diagnosed?
If you notice changes in your eyesight, an eye specialist (ophthalmologist or optometrist) can confirm a diagnosis through a comprehensive eye exam. To diagnose a cataract, your doctor will assess your vision, examine the physical structure of your eye, and perform the tests as given below:
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Visual Acuity and Refraction Test One of the first steps is to evaluate how clearly you can see. During this test, you will be asked to read letters of different sizes from an eye chart, with each eye tested separately. The results help the doctor measure the sharpness of your vision and determine whether corrective lenses can improve it.
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Slit Lamp Examination A slit lamp is a specialised microscope that uses a bright beam of light to examine the eye in detail. This test helps the ophthalmologist closely inspect different parts of the eye, such as the cornea, iris, and lens, making it easier to identify lens clouding and assess the severity of the cataract.
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Retinal Exam (Opthalmoscopy) Pupils are dilated with special eye drops, and the doctor examines the back of the eye (i.e., the retina) to ensure the vision loss is not due to another underlying condition, such as glaucoma or macular degeneration.
How is a Cataract Treated?
The treatment for cataract depends on how much it is affecting your vision. The following two options are generally recommended by doctors:
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Eyeglasses and Vision Aids In the early stages, some people may find that updated eyeglasses, stronger lighting, or other vision aids help them manage their symptoms. However, once cataract begin interfering with daily activities such as reading, driving, or recognising faces, these may not be effective.
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Cataract Surgery Cataract surgery is the most useful treatment for cataract patients. During the procedure, the surgeon removes the lens that is causing the vision problems and replaces it with a clear artificial lens. The surgery is usually performed as a day-care procedure, meaning you can return home the same day. Complications are very rare in this surgery, but on rare occasions, eye infections, swelling, irritation, pain, and even recurring cataract can happen.
Can Cataract be Prevented?
There is no guaranteed way to prevent a cataract. But the following precautions can help to some extent in delaying their progression as you age:
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Schedule Routine Eye Check-ups: Regular eye examinations can help identify cataract and other eye conditions before they begin affecting vision significantly.
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Sun Protection: When spending time outdoors, wear sunglasses that offer UV protection.
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Avoid Smoking: Smoking leads to an increased risk of cataract. Quitting tobacco can benefit both your eye health and overall well-being.
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Manage Chronic Health Conditions: Health issues such as diabetes can increase the likelihood of cataract development. Following your doctor's treatment plan can help reduce this risk.
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Healthy Diet: Include plenty of fruits, vegetables, and other antioxidant-rich foods in your meals. A balanced diet supports long-term eye health.
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Limit Alcohol Consumption: Excessive alcohol intake may contribute to cataract formation. Consuming alcohol in moderation can help reduce this risk.
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Use Steroid Medications Carefully: Long-term use of steroid medicines should only be continued under medical supervision, as they may increase the risk of cataract in some individuals.
What is the Prognosis of Cataract?
The general outlook for people with cataract is very good, especially when they receive early diagnosis and treatment. Prognosis depends on several factors, including the type and severity of the cataract, whether it is in one or both eyes, whether there are other eye or medical conditions present, and how early the cataract is treated.
Cataract surgery restores vision and quality of life for most people. Most patients see a dramatic improvement in vision after the surgery, especially if they follow the eye doctor's recommendations for medications, follow-up visits, and care during the recovery. Early diagnosis and appropriate intervention often provide the best visual outcome.
Does Health Insurance Cover Cataract Surgery?
Yes, most health insurance plans cover cataract surgeries, even though it is typically performed as a daycare procedure that does not require an overnight hospital stay. Coverage generally extends to inpatient hospitalisation charges, pre-hospitalisation expenses such as diagnostic tests and ambulance costs, and post-hospitalisation expenses related to recovery and follow-up care.
However, coverage is usually subject to a specified waiting period of 1 to 2 years and sub-limits, which may cap the amount reimbursed for the procedure.
As coverage terms, waiting periods, and sub-limits vary from insurer to insurer and from policy to policy, it is best to read your policy documents carefully to fully understand exactly what is covered under your plan.
How Much Health Insurance is Required for Cataract Surgery in India?
Treatment generally requires cataract surgery, which helps an individual live a good quality life. It may be expensive, depending on the severity of the case and considering the pre and post hospitalisation expenses and sometimes repeated surgeries may also be performed. A health insurance cover with a sub-limit of at least ₹2 to 5 lakh is strongly recommended for the cataract surgery to ensure adequate financial protection against treatment expenses.
FAQs
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What is the main cause of cataract?
Ans: The most common cause of cataract in eyes is ageing. As people grow older, the proteins in the eye's lens break down and clump together, causing the lens to become cloudy and affecting vision. -
Can I live with cataract without surgery?
Ans: Improved vision aids like updated eyeglasses and brighter lighting can help alleviate symptoms in the early stages. However, as cataract progresses and begins interfering with daily activities, surgery becomes necessary. -
How serious is a cataract?
Ans: Cataract is a serious eye condition that can lead to significant vision loss and even blindness if left untreated.
