Vision Flashcards
Structure of sclera
White part the eye
Collagen and elastin fibres
Function of sclera
Provide attachment for muscles
Structure of cornea
Clear part of sclera
Function of cornea
Acts as fixed lens that allows light into eye
Structure of the iris
Coloured part of the eye
Function of iris
Control opening of pupil
Structure of lens
Transparent fibres in clear membrane
Function of lens
Fine focusing
Two humors
Aqueous humor
Vitreous humor
Structure of aqueous humor and vitreous humor
Gel liquid filling eye
Function of aqueous and vitreous humor
Maintain shape of eye
Provides nutrients to cornea + eye lens
Structure of retina
Internal membrane with photoreceptors
What 2 photo receptors does the retina contain
Rods
Cones
Function of retina
Convert light to electrical signal
Why is the optic nerve described as a blind spot
No photoreceptors
Function of optic nerve
Transmit electrical impulse from retina to brain
Why is the shape of the lens important
Curved shape allows fine focus
What is accommodation
The process where an eye changes optical power to focus on an object depending on distance
What presbyopia
When the lens hardens with age
Can’t accommodate near focus
Push things far
Choroid
Provide oxygen + nutrients to outer retina
Sclera
Choroid
Retina pigment epithelium
What is the retinal pigment epithelium
Pigment layer for light absorption
Photoreceptors
Rods + cones
Where are rods found
Retina
Where are codes found
Fovea
Name of light sensitive pigment in rods
Rhodopsin
Name of light sensitive pigment found in cones
Iodopsin
Acuity of cones
High visual acuity
Acuity of roles
Low visual Acuity
Resolution power of rods
Poorly resolved images
Resolution power of cones
Well resolved image
Which one is sensitive to colour
Cones
Red Green Blue
What type of light are rods sensitive to
Dim light
Why are rods described as monochromatic
Not sensitive to colour
Phototransduction
Conversion of light into electrical signals
Steps of phototransduction
Light changes rhodopsin structure
Change permeability to sodium
Why are 2 eyes better than 1
To make 3D model of world