Eye Tracking Tech – How It Works And What It’s Used For

Eye Tracking

Eye Tracking Technology


Let’s start with the definition of Eye Tracking. As the name suggests and simply put, it is the measurement of eye activity. To dig a little deeper, it means recording the position of the eyes (point of gaze) on a 2D screen or in a 3D environment.  This is done by tracking the corneal reflections to visual attentions.

This allows us to pinpoint the elements on the screen which grab the immediate attention of the viewer. It gives a very good idea about the elements that attract above average attention and similarly if anything is being overlooked or ignored. We can find out the order in which the viewer notices the things on the screen and how they compare to each other.


Let us take a look at the basics of how this technology works. The underlying concept, known as pupil center corneal reflection (PCCR) is not hard to understand. It utilizes near infrared technology and a high-resolution camera to track the movement of the eyes. The near infrared light is directed towards the center of the eyes where are the reflected by the cornea. These reflections are visible in the camera and help track the movement of the eyes.

The infrared light is necessary for eye tracking and it wouldn’t be possible with normal light such as that from a table lamp. The reason behind this is that eye tracking depends majorly on the accuracy of gaze direction measurement. For a proper measurement, a clear reflection needs to be recorded by the camera. This is only possible with infrared light.

The visible spectrum of light creates uncontrolled reflections whereas the infrared light is unperceivable to the human eye and allows the camera to properly measure the gaze direction by passing directly through the pupil and reflecting back from the iris.


Based on the situation, there are two types of eye trackers. If you are sitting in front of a screen, the remote tracker is preferable which tracks the movements of the eye from a difference and is usually mounted under the screen. It allows you to sit in front of the screen without any attachments. However, if you are to interact in a 3D environment a mobile tracker is used which tracks the movement of the eye from close range and is attached to a lightweight eyeglass frame.


Virtual reality is all about immersion. Making use of eye tracking technology will open new avenues for VR technology. This will also reduce the number of pixels drawn by 30-70% resulting in a higher processing power and a higher frame rate per second. This will also solve the graphics distortion problem that is sometimes seen in such applications.

Games have always used some kind of input methods like the mouse, keyboard, joystick or a controller to understand where we are looking at. It will make gaming a brand new experience where the screen will automatically know where we are looking at and won’t need to be directed there manually.

It will help early diagnosis and treatment of infants. “There is an increasing interest in using eye tracking to help diagnose — and potentially treat –neurological disorders,” says Bryn Farnsworth, science editor at biometric research company iMotions. “For example, infants usually like to look at images with people’s faces—scenes that have a social element.”

With eye tracking technology, online advertisers will be able to measure exactly how many actual human eyes actually view their ads when they appear on the page. While gaining precise metrics would be nearly impossible until such time as every computer and mobile device is embedded with eye tracking technology, using eye tracking does give insights into how users interact with ads.

Eye tracking still has a long way to go before it becomes a part of our daily lives. However, it is evident that it will revolutionize a lot of aspects of our lives and will have a great and positive impact.

Author: -Ali Vaqar. A budding engineer, wanting so much from life and making each day count.
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