The aim of this research is to determine how the human eye reacts to light emitting diode (LED) light and the effects it causes to the human eye using the single axis led eye tracker system. The main aim is to examine how the eye reacts different levels of exposure to the LED light which come from different sources like mobile phones, computer monitors, television screens and other sources such as indoor and outdoor lights.
Eye tracking is a process used to measure the point of gaze and the motion of the eye relatively to the head position. The eye tracker is device used to measure the eye positions and movements. There are several categories of eye trackers varying according to the research objectives and include those measuring the movement of an object and they are attached to the eye, secondly we have optical trackers and these do not have direct to the eye and finally there those for measuring electric potentials using electrodes placed around the eyes.
Light emitting diode is a light source which uses a two lead semiconductor to emit light when activated. LEDs emits visible lights of low and high intensity which varies in wavelengths and brightness. Led lights sources are most commonly used in commercial environments as wells as many homes to as cheap and energy saving light source.
This experiment was set up to determine the reaction of the eye to different led lights of different frequencies and wavelengths. The main lesson of this experiment is to show the react to led light the caused by them to eye. It also examines the effects of different LED light to eye when it is exposed to them for a certain duration. Factors that cause the eye to react such as temperatures, light color, the intensity and frequency of these lights are also taken into account.
Single axis led tracking system Micromite.
This is a system for tracking the eye reaction when exposed to LED lights. The system is a 28 pin Micromite that consist of the PIC32 chip and a capacitor and uses special hardware devices to make the program easier to interact with the external world( Hansen, Hammoud,2007). They include infrared remote control receiver and transmitter, temperature sensor, battery backed clock LCD displays, numeric keypads and servos. This experiment uses different parameters like the duration of exposure to the LED light, the light intensity i.e. too much brightness, dim light. It also uses parameters like varying temperatures and the frequency of the light to observe how the eye react when exposed to such conditions. The micromite and the VPixx_software allows for change and modulation of different factors such as the colors, light intensity, the angle of exposure and picture patterns among other conditions used in this research. The eye reaction is observed once it is exposed to the LED light and the immediate effect they cause to eye.
Below are the diagrams of the fully set up Micromite and LCD display used in the research to track various eye reactions by varying conditions of the light.
It uses the following inputs:
IR devcode, Keycode,IR_int
<Body of program>
Print “received device =”Devcode””
The pins are used for differents during the experiment.
The basic circuit for the 28 pin Micromite.
It is used to display different lights produced by LEDs and there range and frequency. The lights produced are tracked to monitor the human eye reaction to the lights. In this experiments the display are modulated using the command LCD INT to use different pins to display different lights.
The human eye reacts differently to different led lights depending on the intensity and duration the eye is exposed to the lights. The eye when exposed to high intensity light or too much brightness or hot it blinks, experiences some pain, there also natural aversion from the light source to avoid and the pupil also constricts (Curatu,Rolland, 2009). This eye reaction depends on the frequency of the light, the temperature and the duration of exposure. The body also reacts to these lights and takes the protective measures to protect the eye from damage.
Energy saving LED technology is one the best way of reducing electricity demands in commercial and residential lighting but has adverse effect to the human eye and the body in general. The exposure to LED light has numerous effects to the eye and can cause irreparable damages to it. Continuous and prolonged exposure to computer monitors, mobile phones and television screens can cause damage to retinas of the human eye which may lead to blindness.
The eye reacts differently to each condition to protect itself. High light intensity and brightness causes eye constriction to protect the retina (Curatu, Rolland, 2009). The eye also turns away from the direct source and sometimes irritation is experienced causing discomfort or the eye to close. Also when exposed to high brightness the eye constricts to protect the retina.
Also the exposure of light at night may also cause damage or discomfort to eye, especially the exposure to dim and colored LED lights emitted in disco clubs and other environment. Protective measures are required to ensure one is exposed to these lights so as to avoid the damage they can cause to the eye. This will reduce cases of the eye damage and other discomforts experienced when one is exposed to the lights.
Though LED sources of light are cost friendly and energy saving they may have adverse effects to the human eye which may damage the retina or can cause both partial and permanent blindness. Preventive measures should be taken to ensure one is well protected from the damages caused by the LED lights. One should avoid spending long hours to computer monitors, television screens and other LED light source to avoid the damage to the eyes. Also one should avoid too much brightness when using devices that generates these lights. One should protective devices like the shades when working in places where there is too much bright light or where they be exposed for long durations.
In addition to the eye damage LED lights have the adverse effects to the human body depending on the exposure. They include skin lash, cancer and other health effects. Those affected should avoid UV light emission sources and use other alternative sources of light energy to protect their eyes and body from the danger of these light.
Iannizzotto L. and La Rosa F., (2011) Competitive combination of Multiple Eye detection and Tracking Techniques, IEEE Transactions on Industrial Electronics,
Curatu, C. E., & Rolland, J. P. (2009). U.S. Patent No. 7,522,344. Washington, DC: U.S. Patent and Trademark Office.
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Coutinho, F. L., & Morimoto, C. H. (2013). Improving head movement tolerance of cross-ratio based eye trackers. International journal of computer vision,101(3), 459-481.
Hansen, D. W., & Hammoud, R. I. (2007). An improved likelihood model for eye tracking. Computer Vision and Image Understanding, 106(2), 220-230.