Search Coil Eye Movement Monitors Search Coil Eye Movement Monitors Scleral search coil measurements are standard techniques used in clinical examinations and research projects where eye position must be monitored accurately in three dimensions. These coils are typically powered at 15 to 20 watts at between 30 to 90 kHz.
Smaller boxes are more mobile.
The circular bulge of the cornea will protrude through the center of this annulus and thereby help position and retain the lens on the eyeball during eye movements. The lens is concave in shape, and adheres firmly to the eye because of the surface tension of the thin film of tears between the lens and the eye. The lens is similar to a standard contact lens, except it is a bit thicker. Subjects normally wear these special contact lenses for no more than 35 minutes because they reduce the supply of nutrients to the cornea. During measurements, the subject's head is positioned in the center of the field coil box.