Intro to Opthalmology Flashcards
(29 cards)
What are the 3 layers of the eye? (Outermost to inner)
Fibrous
Vascular
Neural layer
What makes up the fibrous layer?
Sclera
Cornea
What makes up the vascular layer?
Iris
Pupil
Ciliary body
Choroid
What makes up the neural layer? What receptors are in there?
Retina
Optic nerve
Photoreceptors
What is the anterior section filled with?
Aqueous humor
What is the posterior section filled with?
Vitreous humor
What the the pigmented part of the retina?
Macula
What is in the center of the macula?
Fovea
What is special about the fovea?
Has the area of best visual acuity
Due to the large amount of cones
What are cones?
Nerve photoreceptors with high acuity
How does sight work?
- We see light reflect off an object (unfocused)
- Passes through cornea
- passes through Iris
- Goes through pupil (where light enters the eye)
- Though Lens (focused)
- Hits the retina
- Optic nerve carries signal
What is a focal point?
Location where light focuses on retina
Good vision, the focal point is on the retina
What is refraction?
The bending of light to make a focused image
What general cause does most vision problems come from?
Problems in refracting light
What are refractions errors?
Unclear vision due to shape of eye keeping light from focusing correctly on the retina
What is myopia?
Nearsightedness
What causes myopia?
Too much cornea curvature
Eyeball is too long
How do you correct myopia? How does it work?
Concave lenses
Wide view lens that diverges light rays
Makes objects smaller than they are
What is hyperopia?
Farsightedness
AKA as hypermetropia
What causes hyperopia?
Little cornea curvature
Eyeball is too short
How do we treat hyperopia? How does it work?
Convex lens that converges rays to meet a a single point on the lens
Makes objects larger than they are
What are features of a concave lens?
Spreads out light(divergent)
Focal point in front of lens
Smaller image but clear
Wider viewing angle
What are features of a convex lens?
Focuses light(convergent)
Focal point behind the lens
Magnification
What is astigmatism? What type of images does it produce
Irregular shape of the cornea or lens(football)
Blurry, (starry car lights)