neuro 8.4 vision

Question 1

structure of the eye

Answer 1

-outer fibrous layer: sclera, cornea
-middle vascular layer: iris, ciliary body, choroid
-inner neural layer: retina
-eye is protected by conductiva

Question 2

aqueous humour found?

Answer 2

found in ant an post chambers

Question 3

where is aqueous humour produced

Answer 3

by ciliary body (active NaCl secretion followed by water)

Question 4

Where does aqueous humour go ?

Answer 4

circulated and drained through schemmes canal at the corner-scleral junction

Question 5

function of aqueous humour

Answer 5

-gives nutrients to lens and cornea because they dont have a blood supply
-contibutes to refactive power of the eye

Question 6

what is the intraocular pressure and how is it controlled

Answer 6

-15mmHg
-maintianed by balanced production and reabsorption of aqueous humour

Question 7

glaucoma

Answer 7

-the intraocular pressure increases and eventually presses on the topic nerve causing blindness

Question 8

vitritious humour

Answer 8

-a gel like substance
-different substances can diffuse through it

Question 9

focal length (f)

Answer 9

the distance between the lens and the focal point

Question 10

focal power (D)

Answer 10

the reciprocal of focal length
D=1/f
dioptre

Question 11

convex lens
and how can focal power be increased focal power can be increase by increasing the curvature of the lens

Answer 11

-parallel light rays are converged to a single point called focal point

Question 12

concave lens
what about is focal power

Answer 12

parallel light rays will diverge on the other Side of the lens
-has negative focal power

Question 13

lens system

Answer 13

-2 thin convex lenses close to each other, the focal power of the 2 lenses can be added
-focal length increases

Question 14

what happens when you add a concave and convex lens

Answer 14

-focal power decreases because ur adding a negative and positive focal power

Question 15

lens equation

Answer 15

1/o + 1/ i = 1/f

Question 16

rules of of lens equation

Answer 16

-rays parallel to the optical axis are refracted through the focal point
-rays running through the centre of the lens are not refracted
-when the object is infinitely far (>6m), the image distance is equal to focal length (o+1/ i =1/f)
-when the object comes closer to the lens the image will go farther from the focal point
-the image distance has to be increased to keep the equation balanced

Question 17

accommodation

Answer 17

lens curvature increases

Question 18

importance of accommodation

Answer 18

lens curvature increases =============