Basically, looking into infrared LED's and a camera with an infrared bandpass filter for tracking eye movements; my concerns are whether there would be any potential negative long term effects from constantly illuminating the eye with low power infrared? TIA A

  • 2
    $\begingroup$ Most likely not. We are exposed to IR light every time we step out into the sunlight, so a very small amount from an electronic device designed to follow the eyes is not going to matter much at all. $\endgroup$
    – MattDMo
    Dec 19 '16 at 18:59

I would have said that IR is safe, but some studies have suggested otherwise.

This is a vague study on rabbit eyes:



So there may be a dosimetric exposure limit of some kind that you have to aim for. LED's are very controllable. I'm amazed that they talk about cataracts with a chemically soft, non -ionizing wavelength like IR, because we get IR all day from the sun. If you control the levels to be less than a sunny day, you may find that you can use equivalent of 1hr of sun exposure to run many hours of eye tracking. the figures are a matter of research.


Heat waves are probably infra-red waves. We have these all around us (with great intensity) all the time. A small intensity Infra-red from an LED shall not cause any problem at all even in long terms. Our eyes are evolved to withstand far greater(i.e. around temperature of 45°C) intensities. So, no need to worry.

But since, water is lost from heat waves, do allow subject to blink his eyes frequently.

  • $\begingroup$ LEDs are near IR, while low temperature radiant heat is far IR. Near IR behaves much more like visible light. Like others have said near IR is significantly present in the solar spectrum, so to a degree effects are bounded by what we observe with sunlight exposure. $\endgroup$
    – Real
    Sep 17 '17 at 22:56
  • $\begingroup$ @Real sorry, what do you mean, i don't understand ? Is there any clarification you need? $\endgroup$ Sep 18 '17 at 2:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.