Cataracts

Key clinical points

• The main morphologic types are nuclear sclerotic, cortical, and posterior subcapsular; each affects vision differently.
• Symptoms include glare, reduced contrast, dimming or yellowing of colors, and progressive blur.
• Surgery is indicated when lens opacity impairs the patient’s functional needs, not at a fixed acuity threshold.
• IOL selection (monofocal, toric, extended depth of focus, multifocal) is tailored to the patient’s refractive goals.
• Biometry accuracy is the single largest driver of refractive outcomes.

Types and pathophysiology

Age-related cataract results from cumulative oxidative and biochemical changes in lens proteins. Nuclear sclerotic cataracts harden and yellow the central lens and often induce a myopic shift; cortical cataracts form spoke-like opacities from the periphery; posterior subcapsular cataracts sit at the back of the lens and disproportionately affect near vision and cause glare.

Non-age-related causes include trauma, corticosteroid use, diabetes, intraocular inflammation, and congenital factors, and these should be considered when cataract appears early or asymmetrically.

Evaluation

Assessment includes best-corrected acuity, glare testing, slit-lamp grading of lens changes, and a dilated fundus exam to identify coexisting pathology that may limit visual potential. Optical biometry measures axial length and keratometry for IOL power calculation.

Corneal topography or tomography helps identify irregular astigmatism and screen candidacy for toric or presbyopia-correcting lenses. The macula should be scrutinized, often with OCT, because unrecognized maculopathy is a common cause of disappointing postoperative vision.

Surgical management

Phacoemulsification through a small incision, with implantation of a foldable IOL, is the standard of care. Femtosecond laser assistance is an option for specific steps. The decision to operate is functional: surgery is offered when the cataract interferes with the activities and goals that matter to the patient.

IOL technology now allows surgeons to address astigmatism and presbyopia at the time of surgery. Careful counseling about the trade-offs of premium lenses—particularly potential dysphotopsias with multifocal designs—supports realistic expectations and high satisfaction.

Recovery and refractive outcomes

Most patients notice clearer vision within days, with the eye typically settling over four to six weeks as surgically induced astigmatism and ocular surface disturbance resolve. A short course of topical antibiotic and anti-inflammatory drops is standard, and eye rubbing and heavy straining are avoided early on. Because dry eye and blepharitis worsen transiently after surgery and degrade the refractive result, optimizing the ocular surface before biometry and after surgery meaningfully improves satisfaction.

The refractive target is chosen with the patient: emmetropia for distance, slight myopia for functional near vision, or a blended or premium-lens strategy to reduce spectacle dependence. Realistic counseling about night-vision phenomena with multifocal optics, and about the small chance of a refractive surprise requiring glasses, a laser touch-up, or a lens exchange, is central to a satisfied outcome.