Contact Lenses
121 lenses
Quickly search and sort lenses by brand, replacement, oxygen permeability (Dk), and more.
All 121 lenses →Contact LensesMedicationsGlossarySchoolsHandoutsCalculators
121 lenses
Quickly search and sort lenses by brand, replacement, oxygen permeability (Dk), and more.
All 121 lenses →237 medications
All the information you need to confidently prescribe drops and drugs for ocular disease treatment.
All 237 medications →238 terms
From aberrant regeneration to zylonite, find concise definitions of ophthalmic terms and optical concepts.
All 238 terms →Epicanthus is a vertical fold of skin that runs from the upper or lower lid toward the medial canthus, usually on both sides.1 In infants the fold is often prominent, running down beside the nose with its concave edge toward the inner canthus.2
5 calculators
Each calculator has its own page you can bookmark. Every result shows its work.
All 5 calculators →Try it · Back vertex power
More calculatorsToric over-refractionDiopters ↔ radiusTranspositionHydroxychloroquine
9 PDFs
Everything from Amsler grids for your patients to clinical guides and tables to use in your practice.
All handouts →A guide for parents on why treatment timing matters, why glasses come first, and how patching, atropine, and digital therapy compare, with PEDIG trial results.
1,816 questions
Timed practice exams with worked explanations and a score breakdown by topic. The first half of Exam 1 is free.
Open exam prep →EyeKnow O.D. Pro adds 3 more full-length exams and custom drills from all 1,816 questions. $179 for 12 months, intro price to March 18, 2027. See Pro plans →
Question of the day · free, no account
*EyeKnow O.D. is an independent study tool. It is not affiliated with, endorsed by, or sponsored by the National Board of Examiners in Optometry (NBEO®). “NBEO” is used here only to indicate exam coverage.
27 programs
Admissions, cost, board pass rates and campus life for every accredited OD program, side by side.
Compare all 27 →Forest Grove, OR · College town · Private