Skip to main content

Lens and cataract questions and MCQs for residents

Lens and cataract, BCSC Section 11, spans lens embryology, anatomy and biochemistry; the pathogenesis and morphology of acquired, congenital and metabolic cataracts; ectopia lentis; and the full surgical pathway, from preoperative assessment, biometry and IOL power calculation through phacoemulsification technique to the recognition and management of intraoperative and postoperative complications.

Board questions reward linking a finding to its mechanism or to the correct next step: a refractive surprise traced to a biometry error, an oil droplet cataract pointing to galactosemia, a subluxated lens that raises suspicion of Marfan syndrome or homocystinuria, or a posteriorly dislocated nucleus managed with anterior vitrectomy and vitreoretinal referral rather than pursuit into the vitreous. Expect vignettes on complex eyes, including pseudoexfoliation, poor dilation, intraoperative floppy iris syndrome and prior corneal refractive surgery, and on postoperative problems such as cystoid macular edema, toxic anterior segment syndrome and endophthalmitis.

Work these cataract MCQs in two passes. First, use the explanations and decision flowcharts to build complication-management algorithms you can reproduce under time pressure. Then return to missed items through spaced repetition and weak-topic drills until IOL formula choice, viscoelastic properties and complication timelines are automatic.

Free lens & cataract practice questions

Lens & cataract questions are in the OphthoMentor app: create a free account to practise them with explanations, flowcharts and spaced-repetition review.

High-yield lens & cataract topics for boards

  • Lens embryology: surface ectoderm origin, Y sutures, Mittendorf dot, epicapsular star
  • Nuclear sclerosis: myopic shift and improved near vision without glasses
  • Posterior subcapsular cataract: corticosteroids, diabetes, radiation; glare and near-vision loss
  • Systemic associations: galactosemia oil droplet, diabetic snowflake, myotonic dystrophy Christmas tree
  • Sunflower cataract: Wilson disease and intraocular copper foreign body (chalcosis)
  • Ectopia lentis: Marfan superotemporal, homocystinuria inferonasal, Weill-Marchesani microspherophakia
  • Pediatric cataract: amblyopia risk, timing of surgery, aphakic and pseudophakic correction
  • Pseudoexfoliation syndrome: zonular weakness, poor dilation, capsular tension rings
  • Intraoperative floppy iris syndrome: tamsulosin and other alpha-1 antagonists
  • Refractive surprise: axial length, keratometry and effective lens position errors
  • IOL calculation after myopic LASIK, PRK or RK: causes of hyperopic surprise
  • Ophthalmic viscosurgical devices: cohesive versus dispersive properties and uses
  • Phaco fluidics: peristaltic versus venturi pumps, vacuum, aspiration flow, surge
  • Posterior capsule rupture: anterior vitrectomy, sulcus IOL, retained lens fragments
  • Suprachoroidal hemorrhage: risk factors, recognition, immediate wound closure
  • Toxic anterior segment syndrome versus infectious endophthalmitis: timing and features
  • Endophthalmitis Vitrectomy Study conclusions; chronic Cutibacterium acnes endophthalmitis
  • Pseudophakic cystoid macular edema (Irvine-Gass syndrome): timing, risk factors, treatment
  • Posterior capsule opacification and complications of Nd:YAG capsulotomy
  • Toric and multifocal IOLs: selection, axis misalignment, halos, reduced contrast

How lens & cataract is examined

Lens and cataract maps to BCSC Section 11. On the OKAP and ABO written examinations it appears as single-best-answer items spanning basic science (lens embryology, biochemistry and the causes of specific cataract morphologies) and clinical decision-making around surgery. Many stems are short vignettes in which the answer hinges on recognizing a systemic association, identifying the source of a biometry error or choosing the correct next step after an intraoperative complication.

The EBO Diploma and FRCOphth written papers cover similar ground and often frame it around safe surgical practice: preoperative risk assessment, complications relevant to consent, IOL selection, and the management of posterior capsule rupture, endophthalmitis and postoperative intraocular pressure rise. Clinical optics overlaps heavily, so expect items that combine lens power, anisometropia and refractive targets.

In oral and clinical examinations, cataract is a frequent case topic: candidates may be asked to assess a patient for surgery, explain an unexpected refractive outcome or talk through a complication step by step. Rehearsing structured answers to these scenarios pays off in both written and viva formats.