The Blind spot Hannah allen P.4

Photoreceptors *Some are used to detect light while othersAre used to detect the absence of light (note The different colors of the photoreceptors).

*These photoreceptors are arranged in certain ways to help us recognize different objects.

*Each photoreceptor “circle” creates what is known as a receptive Field which is connected to a certain cell in theRetina that gives information to and from the brain allowingus to Know what we are looking at and how bright it is.

The dark ones activate in the absence of light

The light onesactivate in thepresence of light

Why is this important to

know?The reason we have a blind spot in our eyes is because that specific part in our eye is MISSING PHOTORECEPTORS!

IN the optic nerve head, neurons come together & travel in groups through the “photoreceptor sheet” to form the optic nerve! The problem with this is that The optic nerve needs some way pass through eye, thus causing there to be no photoreceptors in the part it exits... this is Where your blind spot is!

Optical nerve head

Center of vision

*Blind spot

Pupil

Retina

Optic nerve

LEFT

Right

THE PartsOfTheEye

Test your blind spot! Cover

your left eye with your hand and stare directly into the

cross... Move your attention

left until the dot disappears

Why don’t you regularly notice your blind spot?

Left eye vision Right eye vision

blind spot