All of us have seen the eyes of some animal glowing at us in the dark as we drive by at night, so it is natural to think that the eyes themselves are glowing.
The truth is that the glow is the only reflection of light from some other source It is probably caused by our car headlights, or it may be caused by a flash light. The reason that reflection takes place is that there is a layer of crystalline substance in the eyes of many animals. This substance has the ability to reflect light. Man has almost none of this substance in his eyes.
This reflecting layer also helps the animals see in the dark, which is why they can see better at night than man can. The differences in colour of the light reflected from the eyes of animals are due to the different number of blood vessels in their eyes. An animal that has many blood vessels in its eyes will reflect a reddish glow. If it has fewer blood vessels, it will have a whiter glow.
The truth is that the glow is the only reflection of light from some other source It is probably caused by our car headlights, or it may be caused by a flash light. The reason that reflection takes place is that there is a layer of crystalline substance in the eyes of many animals. This substance has the ability to reflect light. Man has almost none of this substance in his eyes.
This reflecting layer also helps the animals see in the dark, which is why they can see better at night than man can. The differences in colour of the light reflected from the eyes of animals are due to the different number of blood vessels in their eyes. An animal that has many blood vessels in its eyes will reflect a reddish glow. If it has fewer blood vessels, it will have a whiter glow.
