What is the size of a large pupil?

• A. <5 mm
• B. >7 mm
• C. 5-7 mm
• D. 8-9 mm

Answer: (B)

A large pupil means it has dilated beyond the normal resting size. Pupils shrink in bright light and widen in dim light or with dilation drugs. In practice, a diameter greater than about 7 mm is generally considered large. While a pupil can reach 8–9 mm in strong dilation or dark conditions, the common clinical threshold for “large” is anything over 7 mm. This matters because a larger pupil can affect how much of the peripheral visual field you rely on and can influence how contact lenses perform under different lighting, including potential glare or edge effects. Smaller sizes (<5 mm) or the mid-range (5–7 mm) are not considered large.