MAR stands for what in vision testing?

• A. Maximum Angle of Resolution
• B. Minimum Angle of Resolution
• C. Median Angle of Rotation
• D. Minimum Anomaly of Refraction

Answer: (B)

Minimum Angle of Resolution is the measure of the smallest angular detail the eye can distinguish. It describes retinal resolving power in angular terms (arcminutes). In vision testing, acuity is tied to how finely details can be resolved, and MAR provides a precise way to express that by describing the smallest angle of detail that can be seen as separate. For example, 20/20 acuity corresponds to a MAR of about 1 arcminute, meaning details subtend 1 minute of arc at the eye. On the other hand, larger MAR values indicate worse acuity, and the logMAR scale uses the logarithm of the MAR to quantify this. The other options don’t fit because they describe concepts that aren’t used to define how sharp vision is in terms of angular detail.