Eye Flashcards
What are the main structures of the eye?
Cornea, pupil, iris, lens, ciliary body, suspensory ligaments, retina, optic nerve.
What is the function of the cornea?
Protects the eye and refracts light entering the eye.
What is the function of the pupil?
Allows light to enter the eye.
What is the function of the iris?
Alters pupil size by contracting or relaxing.
What is the function of the lens?
Focuses light clearly onto the retina.
What is the function of the ciliary body?
Changes the shape of the lens.
What is the function of the suspensory ligaments?
Connects the ciliary muscle to the lens.
What is the function of the retina?
Contains photoreceptors that produce nervous impulses when exposed to light.
What is the function of the optic nerve?
Transmits visual information from the retina to the brain.
How do images form in the eye?
Light is refracted by the cornea and lens, creating a sharp image on the retina. Photo receptors in the retina produced a nerve impulse and exposed to light. This impulse travels down the optic nerve to the brain which interprets is the impulse as an image
What causes short sightedness?
The lens is too strong or the eyeball is too long.
What causes long sightedness?
The lens is too weak or the eyeball is too short.
How can short sightedness be corrected?
Using concave lenses that bend light rays outwards before they enter the eye.
How can long sightedness be corrected?
Using convex lenses that bend light rays inwards before they enter the eye.
What is colour blindness?
A condition where individuals have difficulty distinguishing different colours.
What are the two types of photoreceptor cells in the retina?
Rods and cones.
What do rods do?
Respond to light and allow vision in low light levels.
What do cones do?
Respond to different colours, specifically red, blue, and green light.
What is the most common form of colour blindness?
Red-green colour blindness.
Who is most commonly affected by red-green colour blindness?
Males, as it is a genetically inherited condition.
