Sight Flashcards
What is Conjunctivitis?
Pink eye
What is Astigmatism?
A vision challenge where the cornea or the lens has an abnormal shape.
What causes Dry Eye?
A decrease in oil production on the eye.
What is Entropion?
Having an inversion by the lower eye lid.
What is Glaucoma?
Having an over enlarged aqueous humor.
What causes Macular Degeneration?
A low supply of blood to the eye.
What is the function of the cornea?
Holds in the aqueous humor and refracts light into the lens.
What is the lens?
The lens focuses light on the retina and is composed of a wax like material.
What is the iris?
The iris is the colour pigmented covering around and over the pupil, constricting and dilating it.
What is the sclera?
The sclera is the white protective layer around the eye.
What is the optic nerve’s job?
The optic nerve connects to the back of the eye with the optic disk, it carries light signals to the brain.
What is the conjunctiva?
The conjunctiva is a membrane that starts under the eye lid and lines the outside of the sclera.
What is the aqueous humor?
The aqueous humor provides nourishment for the cornea and iris and keeps the cornea in place.
What is the Vitreous humor?
The vitreous humor maintains the shape of the eye.
What is the nm rage of the photo receptive cells?
850 to 300
What percent of receptors on the body are photoreceptors?
70%
What are cones?
Cones are photoreceptors that recognize colour with pigmented opines that can detect red, blue and green. Our eyes hold 6 million cones.
What is the nm of red?
560nm
What is the nm of blue?
426nm
How many nm is green?
530nm
What are rods?
Rods are photoreceptors that can detect very slight light but cannot distinguish colour.
How many rods do we have?
125 million
What is the minimum required amount of rid signals to see a flash of light?
10 signals
What compounds make up rods?
Rhopsin
What makes up rhopsin?
Posing linked with 11-cis retinal a prosthetic grout
How are rhodpsin and the matrieral of cones related?
Cone materials are rhodpsin’s homologs, members of the 7TM family.
What is in the outer segment of photoreceptors composed of?
Disks fill up most of the cytoplasm, each lined horizontally.
What structures connect the outer and inner segments?
Cilium
What structures make up the inside of the Inner Segment of these rods?
In the closest compartment, mitochondria, Golgi apparatus and ER take up most of the cytoplasm. In the centre compartment is the nucleus and at the farthest point is the synaptic terminal.
In what area of the eye is the best to use in daylight?
The centre of the eye.
What are problems caused by an eye’s shape?
Myopia, hyperopia and astigmatism.
How is myopia dealt with?
As nearsightedness, focussing light in front of the retina,concave glasses can fix the trouble.
What makes Hyperopia different from myopia?
Farsightedness isn’t focused enough to get it on the retina, and can be reversed with convex lenses.
What makes astigmatism unique?
This is when the eye’s sclera is uneven, making it hard to reach certain parts of the retina.
What causes cataracts?
If dead cells accumulate in the aqueous humor, blocking sight.
What can lead the eye into ARMD?
Deprivation of nutrients to the eye.
What is Melanoma?
Melanoma is a type of cancer that grows in the eye
Can Melanoma occur on the conjunctiva?
It can occur on the conjunctiva
What is the bizarre experiment in which a German scientist used a rabbit and a window?
A German scientist forced rabbits to stare out a window and would randomly kill them and then examine their dead eyes to see the shape of the window on their retinas
What is significance of fovea?
Fovea is the place in the retina where cones are the most concentrated.
What is the choroid?
Choroid is the middle layer of the eye which holds blood.
What is the cornea?
The front of the eye
What bends the lens?
The ciliary body
What are the function of eyebrows?
Keeping sweat from reaching the eye
What are conjunctivas?
Mucus membranes
What is ocular melanoma?
A cancer that causes melanocytes cells that produce dark pigments
