eyelid measurements using digital video processing
The aim of this paper is to present an automatic eyelid measurement system based on digital video processing techniques. Currently, the protocol to measure the palpebral fissure (PF) and the marginal reflex distance (MRD) requires the use of a millimetric ruler. This procedure is subject to error and the accuracy and reproducibility of the results depend on the experience of the examiner. The computer vision system introduced in this paper uses two near infrared light sources synchronized with the camera to robustly detect and track the pupil, and then segment the limbus and the eyelids. The corneal reflection generated by the light sources are used to create a reference point that is used to define the vertical line along which the measurements are taken, and to determine when the patient is actually looking at the camera. Our experimental results show that the system is robust to the presence of eyelashes, glasses, and contact lenses, and the measurements can be accurate to tenths of millimeters.
eyelid measurements eye tracking eye detection