Duke Elder Optics & Refraction

Start with the refractive errors, meaning myopia, hyperopia, astigmatism and presbyopia, what causes each and how each is corrected. Then accommodation and how it changes with age. Then the basic physical optics the exam draws on: vergence, lenses and ray diagrams, prisms and their effect, and the reduced eye as a working model. Then the applied material, covering spectacle and contact lens correction and their respective problems, magnification and low vision aids, and the optical principles behind the instruments you have handled, particularly the direct and indirect ophthalmoscope and the slit lamp. Reading a spectacle prescription correctly is a small skill that appears more often than its difficulty suggests.

Clinical topics have a long tail. There is always another rare condition, and the return on each extra hour falls away. Optics does not behave like that. The syllabus is genuinely small, the question types repeat, and once you can do the calculations you can do them reliably rather than probably. That combination is rare on this paper. In an exam that ranks you against other candidates, the topic everyone else skipped is the one that moves your position.

Work problems rather than reading explanations of problems, because optics only becomes fluent through repetition. Draw the ray diagram every time instead of trying to recall which way the answer went, and check your working against the referenced explanation rather than only checking the answer. Short sessions spread across weeks work far better than one concentrated effort, since the calculations fade quickly and refresh quickly.