The Eye Flashcards
What does it mean when your pupil constricts?
It means that it shrinks, most probably due to bright light.
What does it mean when your pupil dilates?
It means that it gets bigger, most probably because there is not much light.
What does the cornea do?
The cornea focuses light onto the retina. It is clear, colourless, and curved.
What does the lens do?
The lens fine-tunes the focusing of the light onto the retina. It is clear, colourless and curved and can change shape.
What does the retina do?
The retina detects light waves and produces impulses. It contains rod cells, cone cells, and sensory neurones.
What does the iris do?
The iris controls the pupil size. It contains muscles.
What is the scientific term for short-sightedness?
Myopia
What is the scientific term for long-sightedness?
Hyperopia
Short-sightedness is when…..
…..distant objects are blurry
Long-sightedness is when………
……close objects are too blurry.
What is one way of correcting short-sightedness?
Using laser surgery to reshape the cornea
What is one way of correcting long-sightedness
Using converging lenses.
The cells in the retina that cause color blindness are…..
…..cones
What is the eye problem that can be fixed by replacing the lens?
Cataracts
What muscles operate the lens?
Ciliary Muscles
What cells detect low levels of light?
Rods
What causes the pupil to constrict and dilate?
Iris Muscles
What is the correct order of parts of the eye when light hits them: retina, cornea, pupil, lens?
- Cornea
- Pupil
- Lens
- Retina
Can colour-blindness be fixed with surgery?
No
What do rod cells do?
Rod cells detect low levels of light
What do cone cells do?
Cone cells detect colours in bright light
The lens is made thinner and fatter by…..
…..ciliary muscles.
How must the lens be for short distance?
Wide and short
How must the lens be for long distances?
Long and narrow.
For short-sightedness, what sort of lens should you use?
For Myopia, Use a concave lens
The lens should look like this: )(
For long-sightedness, what sort of lens should you use?
For Hyperopia, Use a convex lens
The lens should look like this: ()
