Retinoscopy: Reflexes and Working Distance
Master retinoscopy reflexes, working distance correction, astigmatic meridians, and common NBEO and OKAP exam traps.
3 min readStart lessonKeratometry: Board Exam Essentials
Master keratometry for NBEO and OKAP: what it measures, how to read K values and the exam traps that matter.
2 min readStart lessonLensometry: Lensmeter Exam Essentials
Master lensometry with a lensmeter: verify sphere, cylinder, axis, prism, decentration, and back vertex power for boards and dispensing.
3 min readStart lessonAccommodation Optics for Board Exams
Master accommodation, amplitude calculations, presbyopia, and board-tested near vision concepts for NBEO and OKAP preparation.
3 min readStart lessonPrism Diopter and Prentice's Rule: Exam Guide
Learn prism diopters and Prentice's rule for spectacle lens decentration. Practice base direction, induced prism, and board-style calculations.
3 min readStart lessonSpherical Equivalent for Eye Care Exams
Learn spherical equivalent calculation, the circle of least confusion, common exam traps, and clinical uses for board preparation.
3 min readStart lessonVertex Distance and Effective Power
Learn how vertex distance changes effective lens power and how to convert high spectacle prescriptions for contact lenses.
3 min readStart lessonRigid Lens Base Curve Power
Master base curve selection and tear lens power so your rigid contact lens fits align on the cornea and give the intended effective correction.
4 min readStart lessonMastering the Duochrome Test
Learn how the duochrome test, or red-green test, fine-tunes spherical refraction using chromatic aberration for sharper, exam-ready prescriptions.
3 min readStart lessonPinhole Test: Exam Essentials
Master the pinhole test: its optical principle, exam interpretation, false negatives, and common board-style traps.
2 min readStart lessonCylinder Transposition Made Simple
Learn cylinder transposition fast: add sphere and cylinder, reverse the sign, and rotate the axis 90 degrees.
2 min readStart lessonJackson Cross Cylinder Made Simple
Learn Jackson cross cylinder axis and power refinement for clinical refraction and board-style exam questions.
3 min readStart lessonSchematic Eye: Optics Board Review
Master the schematic eye model, its standard values, and the classic exam distinction between the reduced eye and IOL calculation.
3 min readStart lessonRegular vs Irregular Astigmatism
Learn how to distinguish regular astigmatism from irregular astigmatism using refraction, retinoscopy, keratometry, and topography.
3 min readStart lessonAphakic Magnification for Boards
Master spectacle magnification in aphakia, including why unilateral aphakia needs contact lens or intraocular lens correction.
3 min readStart lesson