Anatomy & Physiology: The Eye

A. Accessory structures of the eye

Orbital Cavity

Bones Optic

Foramen

Supra-orbital Foramen

Fat pads

Ethmoid

Sphenoid

Zygomatic

Maxilla

Frontal

Palatine Lacrimal

A. Accessory structures of the eye

Eyebrow Eyelids Conjunctiva

Lacrimal Apparatus Lacrimal

gland Lacrimal

secretion Nasolacrimal

duct

A. Accessory structures of the eye

A. Accessory structures of the eye

Extrinsic Eye Muscles

Superior rectus Inferior rectus Lateral rectus

Medial rectusInferior obliqueSuperior oblique

B. Structure of the Eye

1. Fibrous Tunic - Sclera & Cornea

2. Vascular Tunic – Choroid, Ciliary body, Lens, Iris, Aqueous humor

3. Nervous (Sensory) Tunic – Retina, Macula lutea, Optic Disc, Vitreous humor

Cornea

1. Fibrous Tunic

Sclera

2. Vascular Tunic

ChoroidAqueous Humor

Iris

Pupil

Lens

Suspensory Ligament

Ciliary Body

2. Vascular Tunic

Vitreous Humor

3. Nervous Tunic

Optic Disc

Retina

Vitreous Humor

Macula Lutea

Retina

Light

Optic Nerve

Optic Disc

Retina

Rods Cones

Retina: Rods vs. Cones

Rods Black & White

Dim Light

All over retina

Cones Green,

Red, Blue

Bright light

Mostly in macula lutea

C. Vision Physiology1. Refraction & Lenses

Refraction – bending of lightLenses

Concave

Convex

Focal point

Real Image

R R

C. Vision Physiology2. Visual focusing

Emmetropic Vision – normal vision & requires no accommodation of the lens (20 ft.)

C. Vision Physiology 3. Refraction problems

a.Myopia – nearsightedness. Eyeball too long.

b.Hyperopia – farsightedness. Eyeball too short

c.Astigmatism – unequal curvature of lens

d.Presbyopia – farsightedness due to age. Lens cannot accommodate. About 45 years.

Snellen Eye Chart

Astigmatism Chart

Emmetropic eye

Myopic eye

Hyperopic eye

Myopic eye

Hyperopic eye

Stereoscopic Vision and Depth Perception

D. Disorders of the Eye

1. Cataracts – hardening & clouding of the lens.

2. Glaucoma – buildup of aqueous humor.

3. Color blindness – sex-linked hereditary condition that results in the absence of one or more types of cones.

a. Monochromates – Black & white

b. Dichromates – blue/yellow or red/green

Color Blind Test

Color Blind Test