Vision Flashcards
Where is the cornea?
It is a dome-shaped transparent front part of the eye
What does cornea cover?
Covers iris, pupil and anterior chamber
What does cornea do?
helps to refract light, providing majority of eye’s focusing power
Interesting cornea fact
has more nerve endings that any other body part
What does the iris do?
controls size and diameter of pupil, controls amount of light let into pupil
Where is pupil?
hole in the centre of the iris
What does pupil do?
lets light enter the eye
What/where is ciliary muscle?
ring of smooth muscle in the middle layer of the eye
What does ciliary muscle do?
- accommodate the viewing of objects at different distances
- changes the shape of the lens inside the eye
what does crystalline lens do?
- helps refract light onto retina
- changes focal distance of the eye by changing shape
where is the retina?
light sensitive tissue on inner eye surface
what is retina part of?
central nervous system
how is an image created?
on the retina through the lens and cornea
what does retina contain?
many layers of neurons
what are photoreceptor cells, what types are there?
- types of neurons that are light-sensitive
- cones and rods
what are rods and cones for?
rods - dim light/black and white
cones - daytime and colour perception
what does optic nerve do?
transfer visual info from the retina to brain
what is optic nerve made of?
over one million nerve fibers
what two parts are part of CNS?
optic nerve and retina
what is optic disc/optic nerve head?
where ganglion cell axons leave the eye and form the optic nerve
what does optic disc do?
- creates a break in the field of vision, making a “blind spot”
- carries 1-1.2 million neurons toward the human brain from the eye
