• Are there eye safety concerns for our self-defense product?


    Question:

    I’m developing a self-defense product for my design class. It uses a bright light to temporarily cause pain and disorient an assailant, similar to a less-damaging form of pepper spray.

    The product would use visible-light LEDs as a light source. Is there a danger of causing lasting damage to our eyesight if we were to use ourselves as test subjects? I've researched the American National Standards Institute (ANSI) standards for maximum permissible exposure to visible light. Provided we stay well within these limits, are there any other safety concerns we should be aware of?


    Answer:

    As a general rule, any light powerful enough to cause pain could potentially cause retinal damage (phototoxicity). Phototoxicity comes from the power of the light source, how close the light source is to the eye, and the length of time the eye is exposed to the light. For any given power, the closer the light is to the eye and the longer the exposure, the greater the chance of phototoxicity. It is never a good idea to test any new technology first on humans.


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