According to the WHO, at least 2.2 billion people globally have distant vision impairment. Among these, cataract affects nearly 94 million, whereas glaucoma accounts for 7.7 million cases. Cataract and glaucoma are the two most common eye diseases that cause vision loss or blindness, especially in the elderly. While both conditions affect eyesight, they differ significantly in their causes, symptoms, and treatment options.
In simple terms:
Let’s explore cataract and glaucoma and their early detection, prevention, and effective management.
The pupil of a healthy eye is naturally greyish-black. When a cataract develops, the pupil appears greyish-white or pearly-white, which is why it’s commonly called Safed Motia (white pearl).
A cataract generally occurs due to clouding of the eye’s natural lens, leading to blurred, hazy, or dim vision. This condition usually develops gradually with age, though certain risk factors can accelerate it.
Cataract is easily diagnosed through a simple eye examination and is completely curable with the help of cataract surgery. During the surgery, the cloudy lens is replaced by a clear artificial intraocular lens (IOL), restoring normal vision.
Glaucoma, also known as Kala Motia, is an eye disease that causes damage to the optic nerve, often due to increased intraocular pressure (IOP) in the eyes. The normal eye pressure falls between 10 and 20 mmHg. When it rises beyond this limit, it can damage the optic nerve, disrupting the transmission of visual signals to the brain. This rise in pressure causes a gradual loss of peripheral vision, leading to complete blindness if left untreated.
Glaucoma is often referred to as the “silent thief of sight” because it usually develops without early warning signs.
Glaucoma is an irreversible disease; however, its progression can be slowed down through:
| S No. | Aspect | Cataract | Glaucoma |
|---|---|---|---|
| 1 | Affected part | Clouding of the natural Lens | Damage to the optic nerve |
| 2 | Main Cause | Ageing, UV exposure, diabetes, and steroid use | Raised intraocular pressure, family history, and vascular issues |
| 3 | Symptoms | Blurred vision, faded colours, glare, night vision issues | Often symptomless until advanced; loss of peripheral vision, halos |
| 4 | Pain | Painless | Usually painless (open-angle); painful and red eye in acute angle-closure glaucoma |
| 5 | Vision loss | Central or generalised blur, reversible after surgery | Loss of peripheral vision, irreversible |
| 6 | Treatment | Cataract surgery to replace the lens | Medications, laser, or surgery to reduce eye pressure |
| 7 | Reversibility | Fully reversible | Not reversible; progression can only be slowed down if detected at an early stage |
If a cataract is left untreated, it may rupture inside the eye, causing a rise in eye pressure, a condition called Phacolytic Glaucoma, where a cataract leads to glaucoma.
In a nutshell:
Every adult above 40 years should undergo a comprehensive eye examination once a year to screen for cataract and glaucoma. Early diagnosis ensures timely treatment and protects against preventable blindness.
