The study of conversion between the pupil diameter measured by eye tracker and the real value

The pupil diameter is one of the main indices in eye movement research. Quantitative analysis of pupil diameter can provide the possibility for in-depth study based on eye research. The aim of this article is description and validation of a method for conversion between the pupil diameter measured by eye tracker and the real value, black-round piece method. Firstly, the diameter value of black-round piece made by ourselves was measured by eye tracker and vernier caliper. After getting the value ratio of the eye movement measurement and caliper measurement, it can be used for calculating real pupil diameter by measurement value by eye tracker. In the article, the camera photography method was adopted to measuring real pupil diameter for validation the black - round piece method. Experimental results showed that all the error percent of pupil diameter from the black - round piece method and camera photography method are less than 5%, verified the availability of using black-round piece method on conversion between the measured value by eye tracker with optical recording and the real pupil diameter value.