Posterior Subcapsular Cataract: Symptoms, Causes & Care

Posterior subcapsular cataract (PSC) is a cloudy patch that forms just behind the lens, right in the visual axis. That location makes it particularly disruptive: even a small PSC can severely affect reading, cause glare halos around lights, and make bright-light situations difficult — often before distance vision is significantly affected. Nuclear cataract (central lens hardening) mainly causes gradual distance blur and yellowing of colours; cortical cataract (spoke-like opacities from the edges inward) causes glare. PSC progresses faster than nuclear or cortical cataract — sometimes within months rather than years — so surgery is often indicated earlier. It's particularly common in people with diabetes, long-term steroid use (inhaled, oral, or eye drops), high myopia, or after eye trauma or intraocular inflammation.

Early PSC symptoms are often missed because distance vision may still test well. Watch for: unusual difficulty reading small print, even with your usual reading glasses; disproportionate glare in bright sunlight or from oncoming car headlights at night; halos around lights (especially while driving after dark); reduced contrast — colours look washed out or you have trouble reading white text on a light background; and vision that's worse in bright light than in dim light (the opposite of most other cataracts). If you notice these — particularly if you have diabetes, use inhaled or oral steroids regularly, or are on chronic eye-drop steroids — see an ophthalmologist. A slit-lamp examination confirms PSC in minutes, and grading determines whether surgery is currently warranted. Diabetics should have an annual dilated eye exam regardless of symptoms.

There's no medical or non-surgical treatment that reverses established PSC. Prescription glasses may briefly help early symptoms, but as the opacity thickens, they lose effect. Cataract surgery — modern phacoemulsification with an intraocular lens implant — is the definitive treatment. Because PSC sits centrally and disproportionately impairs daily reading and glare tolerance, surgery is usually indicated at a lower severity threshold than for nuclear or cortical cataracts. Signs that surgery is warranted: reading and near-work becoming unreliable despite glasses; driving becoming unsafe due to glare or halos; work performance affected; falls or safety concerns. If you're diabetic, ensure blood sugar is well-controlled before surgery — poorly controlled diabetes increases infection risk and slows healing. Modern PSC surgery has excellent outcomes; recovery is quick, and most patients notice significant improvement within days. Slowing new PSC development means addressing modifiable risks: use the lowest effective steroid dose for the shortest time, control diabetes tightly, protect eyes from UV, and don't smoke.