Which two directions share the same extent of 60 degrees?

• A. Superior and Nasal
• B. Superior and Temporal
• C. Inferior and Nasal
• D. Inferior and Temporal

Answer: (A)

Movement in each direction is limited by the way the eye muscles pull and by the shape of the orbit. The eye can elevate about 60 degrees from straight ahead, and it can move inward toward the nose about 60 degrees as well. These two directions share the same angular limit because the same type of anatomical constraints—the paths and attachments of the muscles that move the eye upward and inward, along with the orbital boundaries—restrict motion to roughly the same angle.

Other direction pairs don’t have this shared limit because different muscle groups and orbital structures govern their motion, yielding different maximum angles. So the upward and inward directions end up having the same extent—60 degrees.