Vision

Electromagnetic Spectrum

Higher energy gamma rays, x-rays, ultraviolet. (Low wavelength)

Visible wavelengths

Then lower, infrared, microwave, radiowaves.

5 types of cells

Rod cell, cone cell, horizontal cell, bipolar cell, amacrine cell, ganglion cell.

From photoreceptors to bipolar cells to gangilion cells (vertical flow)

Horizontal flow horizontal and amacrine cells

Only 8 kinds of eyes

Chambered

Compound

Each can have no lens, refractive lens, or mirror lens

Adaptations to low light levels

Frontal eyes, reflecting vision. W frontal eyes, came the possiblity of 3D.

Eyes

Descartes

Took eye of an ox, realized everything we see is upside down. 4

Three properties of object
to encode

Where is it? Retinal location. (depends on this and eye/head location)

How bright is it? Intensity. (Vitamin A+Opsin combination causes signal)

What color is it? Wavelength.

Process

Selective gathering of light energy (reflected light from objects)

Projection and focusing that light on a photosensitive surface;

Converting and encoding that light energy

Consists of:

Cornea, lens, retina.

Photoreceptors (rods/cones) process light and relay info to brain - essentially they count photons

Seeing