Human beings are able to fix their gaze on an object, thanks to fixational eye movements; least known type. Counteracting these movements, leads to neural adaptation. Consequently, visual perception fades.

We use our innovative eye tracker, registered at Iran Intellectual Property Office and is registering at the United States Patent and Trademark Office, to investigate these movements. 8 highly educated normal subjects, with a mean age of 25 years old with an average sleep 6 hours were included. Didn’t drink coffee/tea for 8 hours. Didn’t mention neurologic/psychiatric diseases and didn’t take psychotropic drugs. Intermediate distance (1 m) refractive correction was prescribed. 3 different trials were designed and repeated for 5 times. Each lasted for 4 seconds. The trials included a 100 × 70 cm black area with a white fixed target at its center; a circle with a radius of 1,3 & 5 cm. The subjects were instructed to fixate on the target. The trials were recorded at an isolated acoustic room with fixed illumination of 440 lux. The eye tracker was placed on their head and recording was started. The recordings were analyzed by MATLAB 2015a. P value < 0.05 was considered significant.

All 3 types of fixational eye movements, microsaccades, drifts and tremor were detected. Their frequency were 2.2, 45 and 78 Hz respectively. The variance of each trial in 2 dimensions was calculated. No significance was found between the target size and variance of the movements for subjects.

Although it is believed that visual perception lies significantly on the contrast and contours, but no difference was found for these movements. This leads to the question that if fixational eye movements are exceptional for this rule or the size of the targets are larger than they should be. Keywords: Eye Tracker, Fixational Eye Movements, Target size