6- The Eye Flashcards
What does the eye dictate?
How we see the world
What does the eye detect?
Light waves
What is our vision dependent on?
What electromagnetic waves we see
What does the pupil contain?
Light-absorbing pigments
What is the pupil?
The opening where light enters the eye
What is the pupillary light reflex?
The pupil is bigger in low light conditions and smaller when there is lots of light
What does the pupillary light reflex involve?
Connections between the retina and neurons in the brainstem that control certain muscles
What does it mean that the pupillary light reflex is consensual?
Shining light in one eye will cause both pupils to constrict
What is the sclera?
The white of the eye
What is the iris?
Surrounds the pupil and gives colour to the eye
What is the cornea?
The glassy transparent external surface of the eye which is the barrier to protect the eye
What is the optic nerve?
Bundle of axons from the retina that carries information from the eye to the brain
How is an image formed?
Light emitted by or reflected off objects collected by the eye, refracted by the cornea and refracted onto lens, and refracted and focused on the retina to form images
What is the lens involved in?
Forming crisp images
What is lens accommodation?
Changing shape of the lens
When will light rays be distorted?
If they pass through different means
What is the visual field?
The amount of space viewed by the retina when the eye is fixated ahead
What is visual acuity/spatial resolution?
The ability to distinguish between two nearby points
What is retinal disparity?
Binocular cue for perceiving depth
What is binocular disparity?
Difference between images on the two retinas
What does greater disparity between objects mean?
Objects are closer together
What photoreceptors are in the optic nerve?
None
What is completion?
Information in the blind spot is filled in by the brain
What is the blind spot?
Where the optic nerve is and where information exits the eye
What is visual acuity like in the fovea?
High so you can see better
Where is the fovea located?
Centre of the retina
Are there any blood vessels in the fovea?
No
