What is Eye Tracking?
The so-called “eye tracking” is the method of assessing both the movement of the eye associated with the head of a person or the person’s gaze. The eye tracking can be done through the use of the eye tracker. This is one of the digital devices that were invented to bring convenience for both the optometrist and the patient. The eye tracker is a digital item that was invented to measure both the movement and position of the eye. The eye trackers are being used in product design, the input device related to the computer and human interaction, digital marketing, psycholinguistics, psychology, and visual system. There are lots of ways that an optometrist can use to measure the position and the movement of the person’s eyes. One of the most notable variants of eye tracking is the process with the usage of video images with the position of the eye is being removed. Other ways are using the search coils or the electrooculogram basis.
Different Types of Eye Tracker
The different types of eye trackers have their way to measure eye rotation. Eye trackers usually fall into three different types. The first one is the optical measurement that doesn’t have the direct interaction with the eye, the second one measures the movement of the object, (it is usually the special lenses) and the last one measures the electric potentials through the use of electrodes that are being positioned near the eyes.
This optical tracking is one of the different types of eye tracking that only measures the motion of the eye. The light used on doing this eye-tracking type is infrared. It is commonly reflected in the eye of the person and will be sensed by the camera video or any other types of innovative optical sensors. The data gathered will be examined to know the changes in the rotation of the person’s eye. The camera video accessories usually use the person’s corneal reflection and the features of the pupil center that will track the movements of the eye time after time. The Dual-Purkinje is the more delicate kind of eye tracker. It uses both the back lenses that are in the fourth image of the Purkinje and the reflection of the front cornea that is in the first image of Purkinje. The more delicate type of eye tracking is tracing the features inside the person’s eyes, including the retinal blood vessels that will follow the rotation of the eye. Different optical strategies, specifically those methods that will base on the eyes video recordings, are being used to track gazes of a person and are considered as the cheapest and non-invasive type of eye tracking method.
Eye Attached Tracking
This is the second type of eye tracking that typically uses the accessories that will be attached in the eyes of a person. These eye attachments include the special lenses that have the attached magnetic sensor field or mirror. The eye attachment movement will be measured through a hypothesis that it will not create significant errors when the person’s eye rotates. The measurement that uses the tight special lenses will give the very delicate eye movement recordings. And through the use of the search magnetic coils, it will provide the examiners to have the right study about the underlying physiology and dynamics about the movement of the person’s eyes. This kind of technique will allow the eye movement measurements in torsion, vertical and horizontal directions.
Electric Potential Measurement
The electric potential measurement is the third type of eye tracking. Through the electrodes that will be put around the person’s eyes, an optometrist can measure the electric potentials of the person’s eyes. The stable electric field potential originated from the eyes of a person that can be measured by an eye tracker whether the eye is closed or even in the dark areas. The person’s eyes electric potentials can be created through a negative pole located at the retina and the positive pole that is located at the cornea. The EOG or the Electrooculogram is the signal that was originated from a single pair of electrodes that was positioned in the eyes of a person. If the eye of a person moves from the center to the periphery, the cornea of the person’s eyes will approach the electrode, and the retina will approach the other electrode. Through these changes, the measurement of the EOG signal will also change. However, through evaluating the said eye movement changes can still be tracked by an eye tracker.
Principal Type of Eye Tracking
Since there are different types of the eye tracker, both the glasses and the screen-based eye trackers are the principal types of eye trackers. These two were already used with several research areas and fields, but their usage and results will always be different from each other.
Eye Tracking Glasses
The name indicated that the different mobile items could be perfectly fixed close to the person’s eyes. These mobile items can be fixed on the frames of the eyeglasses that will allow the person to move their eyes and head freely. Noticeably, these eye tracking glasses can be used in your research if you will perform different tasks about the natural environment. One of its disadvantages is that the eye tracking glasses might probably change if the current recordings conduct a significant movement.
Screen-Based Eye Trackers
The screen-based eye trackers will require the patients to take a seat at the front of the monitor and must have contact with the screen-based contents. This type of eye tracker only tracks the movement of the person’s eyes if it was on its limits, which is called as the headbox. This type of principal eye tracker is very convenient to use. Thus, it was being used by many professionals in different fields.
Eye tracking is being used in a wide range of fields. It is beneficial to determine the tight measurement of the eye movement of a person.