Post on 31-Dec-2015
description
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.