EYE: v8

RODS AND CONES:  The rod cells see black and white and the cones see color. When you focus on something,  you are only using your rod cells.

RODS AND CONES:  Unlike the cone cells, rod cells cannot detect color. However, they are ten thousand times more sensitive to light than the cones cells! This extra sensitivity is fantastic for night vision!

RODS AND CONES:  Rod cells look like skyscrapers, with floors stacked on top of each other. These floors are called discs. There are over one thousand discs in a single rod cell!

RODS AND CONES:  Woven Into each of these tiny discs in the rods there are incredibly small protein molecules called rhodopsin. When light enters the eye, it strikes the rhodopsin proteins. This causes a signal to be sent from the rod cell to a cell that lies right above it called a Bipolar cell.

RODS AND CONES:  Each of these bipolar cells has about ten rod cells attached to it. When the ganglion cell fires because the rod cells send messages to it, it sends a message to the Ganglion cell above it.

RODS AND CONES: Ganglion cells have long wire-like axons growing side-by-side that form the optic nerve for each eye. These two optic nerves go to the brain’s eyesight center, the visual copier. 

MESSAGES PER SECOND:  Your eyes are sending messages to the brain at the rate of 30 to 60 times a second.

MESSAGES PER SECOND: Many birds and some insects send messages at 200 times per second!

MESSAGES PER SECOND:  Birds’ auditory cortex operates at a faster level than ours does. We can’t even see what birds are doing sometimes because we don’t transmit messages fast enough.

10. MESSAGES PER SECOND:  Seeing quickly all has to do with the speed of molecular reactions. The light-detecting opsin proteins in them go through a molecular change when light photons hit them.  This happens in several femtoseconds.  That’s a thousand times faster than a trillionth of a second.