The EyeMaria Romo

Sophia GomezChristopher Oviedo

Period: 5

● Cornea- light focus● Sclera- white portion

of the eye● Aqueous Humor

The Outer Tunic

The Middle Tunic

★ Choroid Coat- posterior of ⅚globe of eye and loosely joins sclera

★ Ciliary body- thickest coat

The Middle Tunic cont.● Suspensory

Ligaments- lens further focuses light

● Iris- controls amount of light entering the back of the eye by adjusting pupil size

● Pupil- hole in the eye where light enters

The Inner Tunic● Retina- light sensitive

inner lining● Optic Disc- “Blind

Spot”● Vitreous Body-

internal structure of the eye that helps maintain shape

● Hyaloid Canal- leads to optic nerve.

the Inner Tunic Cont.

● Macula Lutea- yellowish central part of retina

● Fovea Centralis- region of the retina that produces sharpest vision

● Ganglion Nerves

Neurons

1. Visual receptorsa. cone- color sensoryb. rod- light sensory

i. more numerousii. more sensitive

Neurons cont.

2. Ganglion Neurons●M-Type (Alpha or Parasol)- Detect motion● P-Type (Beta or Midget)- Detect details in vision● Non-M, non-P type- Involved in color vision●Photoreceptive ganglion cells- Respond slowly to light

Neurons cont.● Optic Nerve- transmits sensory info

regarding brightness perception, red-green color, contrast, and visual fields.

● Choroid- Vascular layer containing connective tissue between the retina and the sclera. Provides nourishment and O2 to the outer layers of the retina

Accessory organs● lids, brows, and lashes-

protect the eye ● Conjunctival sac- mucous

membrane● Lacrimal gland- produces

tears● Lacrimal Sac- drains tears

from eye’s surface.● Nasolacrimal duct- (tear

duct) excess tears flow through from lacrimal sac.

Accessory organs cont.

Tarsal Glands- secretes and collects mucous and tears.●Punctum Lacrimale●Plica semilunaris●Caruncula

Extrinsic Muscles1. Superior Rectus- rotates eye up

and toward midline.2. Inferior Rectus- rotates eye down

and toward midline. 3. Medial Rectus- rotates eye

towards midline. 4. Lateral Rectus- rotates eye away

from midline.5. Superior Oblique- rotates eye

downward and away from midline.6. Inferior Oblique- rotates eye

upward and away from midline.

Chambers of the Eye

1. Anterior- behind cornea2. Posterior- behind iris, in front of lens

a. filled with aqueous humor and works in balance with anterior chamber to keep eye shape

3. Vitreous- fills up the space behind the irisa. filled with amorphous/ gelatinous fluid to help keep

eye shape.

chambers of the eye cont.

How we interpret sight

● Refraction- it’s an error when you don’t 20/20 vision. The error behind this is that the light is not bending properly when it passes through the cornea and retina of your eye

Cont.

cont.● Convergent vs Divergent waves-

o Structure: vertebrates o Convergence: axons originating from different parts

of the nervous system leading to the same neuron.

cont.

●allows the nervous system to collect, process, and respond to information●to focus: eyes adduct, the ciliary muscles contract, and the pupils become smaller

cont.

● Divergence: impulses leaving

a neuron of a neuronal pool

and then by reaching several

other neurono Ex. one neuron may o stimulate several others,

and so forth.● can amplify an impulse- spreads it to increase number

of neuron within the pool

cont.

● Cones vs. Rods (both are photoreceptors)o Cones

6 to 7 million cones provide eye’s color sensitivity more concentrated on yellow spot (Macula)

o Rods are numerous, about 120 million rods more sensitive than the cones exception not sensitive to color

Cont● Dark vs Light vision- ● The “Dark” vision( scotopic vision): the rods

are responsible for vision under very dim levels of illumination. They provide the capability for seeing colors and resolving better detail ( 20/20 or better)o mainly uses rods during the nighto pigment granules first line of defense against light

cont.

● The “Light” vision (photopic vision): the cones function at higher illumination levels. They provide the ability to discriminate only between shade of black and whiteo mainly uses cones in the day

cont

● Stereoscopic vision- the single perception of a slightly different image from each eye. It simultaneously perceives distance, depth, height, and width of objects. Such vision is possible because the pupils are 2-9mm in diameter.o Pupils- dilate in the dark(3-8 mm) and in the light

they constrict (2-4 mm).

Citation

● "The Accessory Organs of the Eye - Human Anatomy." The Accessory Organs of the Eye - Human Anatomy. N.p., n.d. Web. 06 May 2015.● "The Basics Of Eye Exercises. What Does It Aims To Train?"ImproveEyesightHQ.com. N.p., n.d. Web. 06 May 2015.●Miller, Robert E., II. "The Eye and Night Vision." The Eye and Night Vision. N.p., n.d. Web. 06 May 2015.●Segre, Liz. "The Science Behind the Look of Love." All About Vision. N.p., n.d. Web. 06 May 2015.●Strauss, Olaf. "The Eye and Night Vision." The Eye and Night Vision. N.p., n.d. Web. 06 May 2015.●"Visual Receptors." - RightDiagnosis.com. N.p., n.d. Web. 06 May 2015.