Noninvasive measurement of eye retraction during blinking.

We present a noninvasive technique for high-speed measuring of eye retraction and eyelid position during blinking. The anterior chamber of the eye is illuminated by the slit lamp of a biomicroscope and eye dynamics during a blinking sequence are captured with a high-speed camera working at 500 frames per second. Digital image processing allows quantitative analysis of cornea and eyelid positions during the closing and opening phases of the blinking process. Our method allows simultaneous measuring of corneal retraction, duration of down and up phases, total blinking duration, and average and peak speeds of the eyelids in both phases, thus providing a complete analysis of the blink's transversal motions. (C) 2010 Optical Society of America