What is the doctor testing when he asks me to follow his finger with my eyes?

[East Blythe]

Which part in my eyes can he test by doing this?

[East Brady]

In the eyes exam, doctors are may ask you to follow his finger in the process of Slow tracking, or ""pursuits"" in which the examiner's finger traces an imaginary "double-H", which touches upon the eight fields of gaze. These test the muscles of the eye, as well as the oblique muscles.

[East Branch]

The doctor asks you to follow his finger with your both eyes to determine whether the eye muscles are strong or weak.They also know whether both eyes can move as a team through this test.