Glaucoma vs. Cataract: Understanding the Key Differences

Dr.Vidya Chaudhry, 3 mins read

Envision an ordinary moment transformed by a slight visual disruption: driving through the city’s bustling traffic as the lights blur into halos, or overlooking a loved one's approach from the side. These experiences underscore glaucoma and cataract - two of the most prevalent eye conditions worldwide, often misconstrued as inevitable signs of ageing. Yet, they differ markedly in their pathology, progression, symptoms, and therapeutic approaches.

At Aakash Healthcare Super Speciality Hospital, our ophthalmology team frequently clarifies these distinctions for patients seeking reliable guidance. This article offers a comprehensive yet accessible overview to empower informed eye health decisions.

What is Cataract?

Cataract refers to the progressive opacification of the eye's crystalline lens, the transparent structure responsible for focusing light onto the retina. Over time, proteins within the lens clump together, forming a cloudy barrier that scatters light and impairs clarity. Common reasons for the development of cataract include extended ultraviolet radiation exposure, smoking, diabetes mellitus, prolonged corticosteroid use, and natural ageing, with onset typically after age 60.

Symptoms manifest gradually: diminished vision, heightened sensitivity to glare (especially at night), faded colour perception, and frequent prescription changes for spectacles. Patients describe it as viewing the world through a frosted glass pane. Fortunately, cataract is easily treatable. Modern phacoemulsification surgery, a minimally invasive procedure lasting 15-20 minutes under topical anaesthesia (using eye drops to numb the eye), fragments and removes the defective lens, implanting a foldable intraocular lens (IOL). Success rates generally are over 90%, with most patients achieving independence from wearing spectacles for distance vision. Recovery is swift, often allowing return to normal activities within days. Special intraocular lenses may be used, as suitable for the patient, to allow spectacle-free intermediate and near vision as well.

What is Glaucoma?

Glaucoma constitutes a group of disorders characterised by optic nerve damage, primarily due to elevated intraocular pressure (IOP). The optic nerve, comprising over a million nerve fibers, serves as the eye's communication pathway to the brain. When aqueous humour - a clear fluid produced by the ciliary body - drains inadequately, pressure builds, compressing these fibres and leading to irreversible vision loss. Glaucoma progresses slowly, eroding peripheral vision first and potentially culminating in tunnel vision or blindness if unmanaged.

Risk factors include people aged above 40, family history of glaucoma (genetic predisposition accounts for 50% of cases), myopia, and certain ethnic backgrounds, including the Indian population.

Unlike overt symptoms in cataract, glaucoma is dubbed the "silent thief of sight" because early stages are asymptomatic; damage may exceed 60% before detection. Glaucoma is almost always diagnosed by the doctor on a “routine” eye check-up. Unfortunately, symptomatic glaucoma is often in the advanced stage, and optic nerve damage cannot be reversed. Diagnosis relies on tonometry (measuring IOP), gonioscopy, optic nerve head evaluation via optical coherence tomography (OCT), and visual field testing. Laser trabeculoplasty or minimally invasive glaucoma surgery (MIGS) offers alternatives for non-responders. While vision loss cannot be reversed, early intervention preserves function - regular screening every 1-2 years for at-risk individuals is crucial.

Critical Differences and Prevention Strategies

At their core, cataract is a lens disorder amenable to curative surgery, whereas glaucoma inflicts permanent optic damage requiring lifelong vigilance. Cataract blurs centrally; glaucoma erodes edges in the early stages, progressing to vision loss if untreated.

Some prevention tips:

• Protect eyes with UV-blocking sunglasses
• Maintain glycemic control, avoid smoking
• Adhere to annual eye exams post-40

In India, community programs like free screening camps have detected thousands of cases early, averting disability. Do not delay a check-up, as vision is irreplaceable. At Aakash Healthcare, our state-of-the-art diagnostics and personalised care ensure optimal outcomes. For booking an eye check-up, call 88 000 159 05.