For anyone wondering why they would need to see polarized light: I actually looked into this a few months ago!
Other animals that are trying to blend in with the environment often use countershading appear less conspicuous. The problem with this is that this method can’t replicate the polarization of the light behind them, making them stand out if you can see that sort of thing. ((Sunlight in the ocean is always polarized based on the direction of the sun (look up fresnel equations for s and p polarized light))). Even transparent creatures will interrupt the polarization in some way, so this is a very useful skill to have.
More specifically, polarization changes with the angle of reflection of the surface towards the detector / eye / camera, so every bump in the surface gets a color gradient different from the surroundings when seen by a polarization sensitive eye
For anyone wondering why they would need to see polarized light: I actually looked into this a few months ago!
Other animals that are trying to blend in with the environment often use countershading appear less conspicuous. The problem with this is that this method can’t replicate the polarization of the light behind them, making them stand out if you can see that sort of thing. ((Sunlight in the ocean is always polarized based on the direction of the sun (look up fresnel equations for s and p polarized light))). Even transparent creatures will interrupt the polarization in some way, so this is a very useful skill to have.
More specifically, polarization changes with the angle of reflection of the surface towards the detector / eye / camera, so every bump in the surface gets a color gradient different from the surroundings when seen by a polarization sensitive eye