Why didn't my cat and fish go blind when a green laser pointer was pointed directly in its eyes?

Question

I checked my surveillance cameras and saw my son bringing his friend over who had a green laser pointer. They purposely pointed it directly in my cat's and my fish's eyes but as far as I know, both my cat and fish can still see fine. How come this didn't blind them? I read that green laser pointers are 10x as bright as red ones and could blind someone after more than 0.25 second exposure.

Answer 1

When laser, or other light, is focused on the retina, it can cause damage. The retina itself is transparent, but the pigment layer beneath it (Retinal Pigment Epithelium) has melanin pigment which can absorb the light. If there's enough light energy, the light energy can become thermal. This heat energy causes the damage. Any time we do laser to the retina, the size of the spot being used, the amount of time that spot of light is focused on the RPE, and the intensity of the power are factors we consider. Initially, the laser spot is place out to the side of the retina so that the initial spot doesn't damage anything 'important' or cause a hemorrhage or hole. The energy is then slowly increased until a very light, or cream colored spot is noted. Usually this spot is smaller than the actual spot, so it's sort of a threshold power/time/size thing.

Answer 2

You don't really think that laser pointers available to the public that easily are capable of blinding someone that fast do you ?

Answer 3

I checked my surveillance cameras and saw my son bringing his friend over who had a green laser pointer. They purposely pointed it directly in my cat's and my fish's eyes but as far as I know, both my cat and fish can still see fine. How come this didn't blind them? I read that green laser pointers are 10x as bright as red ones and could blind someone after more than 0.25 second exposure.