Part I ABS®


Applied Basic Science



The Part I ABS Applied Basic Science examination tests the underlying basic science concepts necessary to enter the clinical practice of optometry.

The Part I ABS examination consists of 350 scored items and 20 non-scored pre-test items. Candidates will not know which items are scored and which are pre-test. The exam is two sessions in length, each session consisting of 185 items. Candidates will have 4 hours to complete each session. The morning session includes an additional 15 minutes devoted to a tutorial and the reading and signing of a non-disclosure agreement (NDA). There is an optional break of up to 45 minutes between the morning and afternoon sessions.

Student candidates must be in the spring of their third academic year to take the Part I ABS exam. There will be three opportunities to sit for the exam prior to graduation.



Most items on the Part I ABS exam require candidates to choose the single best or correct answer. Approximately 10-15% of the items on the exam are multiple-response (MR) items; with MR items the required number of responses (2, 3, or 4) is indicated after the item stem. MR items are scored as completely correct or incorrect; there is no partial credit.

On the Part I ABS examination, drugs are referenced only by generic name. Candidates can see a sample version of this drug list by going to the "EXAM INFORMATION" tab. It is important that candidates note that the sample drug list is not intended to be a study guide, nor is it necessarily a complete list of drugs that may appear on the ABS exam. Candidates should also be aware that the drug list will include only those drugs that have commonly used trade names. Drugs such as penicillin will not appear on the list. Trade names are sometimes used on the Part I ABS exam when referring to preservatives since some preservatives cannot be identified by a single generic ingredient.

Candidates should note that the non-possessive form will be used on the Part I ABS exam for eponymous terms (e.g., Horner syndrome will be used rather than Horner's syndrome, and Descemet membrane will be used rather than Descemet's membrane). This usage is in accordance with the growing trend in medical and scientific writing to remove the possessive when using eponyms.



A tutorial for the Part I ABS exam can be found on the "EXAM INFORMATION" tab. Candidates are strongly encouraged to go through the tutorial prior to exam day so that they can become familiar with the mechanics of taking the exam by computer. Candidates will only have 10 minutes to go through the tutorial on the morning of the exam, and candidates may have difficulty completing the tutorial in that amount of time.

Links to the Part I ABS Content Matrix and the Part I ABS Content Outlines can be found in the "EXAM INFORMATION" tab.