Nasal extent of the monocular field is 60 degrees.

• A. 75 degrees
• B. 60 degrees
• C. 105 degrees
• D. 50 degrees

Answer: (B)

The main idea is how far one eye can see toward the nose without the nose blocking the view. In a typical eye, the nasal boundary of the monocular field is about sixty degrees from the central line of sight. That means you can detect objects up to roughly 60 degrees toward the nose with one eye, while the temporal side extends farther, giving a larger total monocular field.

This nasal limit is a standard reference in eye exams and helps define the normal monocular field. The other numbers don’t fit this typical anatomical boundary: seventy-five or one hundred five degrees would imply a wider nasal field than is anatomically typical, and fifty degrees would be smaller than average, not representing the normal baseline.