3 ms·

Could you use a laser at a frequency that the cornea is opaque to?

• wnkrshm 5y ago
  Then you injure the cornea. That's why they use UV lasers for laser surgery, because the cornea absorbs it. Edit: I recently had a small corneal erosion from my eye drying out over night (eyelid was pulled open by sleeping in a weird posture) and I had 30% vision for 2 days on that eye. The cornea contributes about 40% (iirc could be more) to the total refractive power in the eye. If you have a UV-spot that melts moskitos dancing around on that for half a second...
  • cobbzilla 5y ago
    What about an infrared laser? Something where a microburst would melt delicate insect wings, but a direct hit on a human eye would just warm it up a tiny bit. Possible?
    • detaro 5y ago
      You basically can't make laser pulses safe and melt things at the same time, because by nature of having the energy in a short pulse created heat doesn't have time to distribute, so it doesn't matter if you hit a tiny thing or a tiny spot on a larger object, the damage done locally is the same.
      • cobbzilla 5y ago
        I’m confused, are you saying that the minimum amount of energy in an infrared pulse sufficient to melt a fly’s wings (< 1mm) would necessarily also damage a human eye? I have to believe there is a threshold value of safety, particularly with IR. You can tell me I’m wrong, but please provide a bit of physics to justify it.