The Eye Flashcards
Type of radiation light is
Electromagnetic
Photon
Particle of light
Speed of light
299,792,458 m/s
Wavelength
Difference between peaks
Frequency
Number of waves that passs a given point per second of time
Wavelength of colours from red to purple
Gets longer
Frequency of colours from red to purple
Gets more frequent
Structure of the eye
Cornea, sclera, pupil, iris, lens, retina, fovea, optic nerve
Cornea
Transparent outer coating of the eye
Principal means of focus
Sclera
White opaque outer coating of eye
Pupil
Circular hole in the centre of the iris, through which light enters
Iris
Visible through the cornea of the eye
Lens
Focuses an image on the retina by accommodation
Changes shape to adjust the eye’s focus for stimuli located at different distances
Retina
Array of photoreceptors and neural circuitry that covers back surface of the eye
Phototransduction
Transformation of photons into electrochemical energy
Done by the retina
Fovea
Where the image falls in the eye
Optic nerve
Bundle of nerve fibres that carry nerve impulses from the retina to the brain
Chambers of the eye
Arterior, posterior, vitreous
Location of arterior chamber
Between cornea and iris
Location of posterior chamber
Between iris and lens
Location of vitreous chamber
Behind the lens
Pathway to the optic nerve
Light > cornea > pupil > lens > retina > optic nerve
Types of photoreceptor cells
Rods and cones
Function of rod cells
Vision at low light levels
Sensitivity to darkness
Function of cone cells
Vision in bright light
Colour and fine details
Numbers of rod cells in the eye
120 million
Numbers of cone cells in the eye
6 million
Location of rod cells
Peripheral retina
Location of cone cells
Peripheral retina and fovea
Blind spot
No photoreceptors
Peripheral vision falls on it and isn’t noticed
Location of blind spot
Retina, where the optic nerve leads to the brain
