Nerve06/eyes and ears/photoreceptor cells 2

There are two kinds of photoreceptor cells: rod cells and cone cells. The cone cells have higher resolution, and are used for distinguishing colors and shape. They are located around the macula, which is in the center of the retina. Meanwhile, rod cells, which have less resolution, are located around the periphery of the retina.

Therefore, eyesight resolution is not constant throughout the retina. This is because the cone cells are dense in the center of the retina and, adjustment is made in order for the light from the object being watched to reach the macula. Try reading this material without moving your neck or eye. You can easily tell that the resolution within your visual field is not constant.

There are 3 kinds of cone cells for specific sensitivity to3 colors: red, green and blue. The ratio of stimulation to each cell determines the color being sensed.

Challenge Quiz

<GIFT> //LEVEL:3 //RAND The {=cone.~rod} cells are rich in the center of the retina.

//LEVEL:3 //RAND The {~cone.=rod} cells are rich in the periphery of the retina.

//LEVEL:3 //RAND The cone cells are rich in the {=center.~periphery} of the retina.

//LEVEL:3 //RAND The rod cells are rich in the {~center.=periphery} of the retina.

//LEVEL:2 //RAND The resolution of the cone cells is {~low.=high}.

//LEVEL:2 //RAND The resolution of the rod cells is {=low.~high}.

//LEVEL:3 //RAND The eyesight resolution is homogeneous throughout the retina. {~true.=false}

//LEVEL:3 //RAND There are cone cells which are specifically sensitive to red, green and yellow. {~true.=false}