I’m a Scientist is like school science lessons meet the X Factor! School students choose which scientist gets a prize of $1000 to communicate their work.
Scientists and students talk on this website. They both break down barriers, have fun and learn. But only the students get to vote.
This zone is the Organs Zone. It has scientists studying health and disease in various parts  of our bodies. Who gets the prize? YOU decide!
The red color comes from light that reflects off of the retinas in our eyes. In many animals, including dogs, cats and deer, the retina has a special reflective layer called the tapetum lucidum that acts almost like a mirror at the backs of their eyes. If you shine a flashlight or headlights into their eyes at night, their eyes shine back with bright, white light.
Humans don’t have this tapetum lucidum layer in their retinas. If you shine a flashlight in a person’s eyes at night, you don’t see any sort of reflection. The flash on a camera is bright enough, however, to cause a reflection off of the retina — what you see is the red color from the blood vessels nourishing the eye.
Many cameras have a “red eye reduction” feature. In these cameras, the flash goes off twice — once right before the picture is taken, and then again to actually take the picture. The first flash causes people’s pupils to contract, reducing “red eye” significantly. Another trick is to turn on all the lights in the room, which also contracts the pupil.
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Because you’re a vampire.
Or what Hannah said.
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Yep, reflection.
It’s more to do with whether the iris has reacted and narrowed in response to the huge bright light from the flash (no red-eye), or whether it has not and remains wide open where light can be reflected back (red-eye).
I see Hannah’s all over this too 😉
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