Can someone explain to me about eyes reflecting back light?

Question

i get really confused , while learning something!

Answer 1

“It's quite simple, really. If I'm the Moon, and I'm traveling at the speed of light in the general direction of your eye, and I then collide with it in the manner of a large circular object consisting of bread, cheese, pepperoni, and tomato sauce, then there is naturally an impact - which can be theoretically termed, in a word, amoré.'”

~ Albert Einstein

Answer 2

Whats to explain? The eyes reflect some light as all surfaces do. The retina is rich in blood vessels and the reflection is tinted red.