Fundamentals of Sensation and Perception LIGHT AND THE EYES

ERIK CHEVRIER

NOVEMBER 10, 2015

Video Light Waves – Visible and Invisible

Is Light a Particle or Wave?

Particles and Waves

What are all those Floaty Things in Your Eye?

The Evolution of the Human Eye

The Human Visual System

Light Electromagnetic Radiation

Light is a wave◦ Wavelength

Light is a particle◦ Photon

◦ Absorbs◦ Reflects◦ Refracts

Optic Array

Field of View

Acuity and Eye Movements

Extraocular Muscles

Structure and Function of the Eye

Lens and Accommodation

Retina

Retina

Retina

Rods and Cones

Rods and Cones

Rods and Cones

Rods and Cones – Operating Range

Dark Adaptation

Retinal Ganglion Cells (RGC)

Receptive Field

RGC Center-Surround Receptive Field

RGC Center-Surround Receptive Field

Lateral Inhibition

Disorders of Vision Strabismus – Disorder of extraocular muscles where the two eyes are not allied with one another. Causes blurry vision.

Amblyopia – Neural signals from one eye are not processed properly. Fine vision does not develop in that eye.

Disorders of accommodation ◦ Myopia◦ Hyperopia◦ Presbyopia◦ Astigmatism

Disorders of Vision Glaucoma – Intraocular pressure is too high for a person’s eye caused by a blockage of the openings that let aqueous humor drain from the anterior chamber.

Floaters – Shadows on the retina thrown by debris within the vitreous humor.

Phosphenes – Brief, tiny flashes in the person’s field of view not caused by light but a variety of other causes.

Retinitis Pigmentosa – an inherited condition which there is gradual degeneration of the photoreceptors over many years.

Macular Degeneration – Damage to photo receptors in the macula. ◦ Dry – Cells degenerate in the pigment epithelium which cause the loss of photo receptors overlaying

those cells. ◦ Wet – New blood vesicles grow under the retina, leak fluid, bleed and scar.

Questions? Have a great day!