The Eye Flashcards
What is the cornea
The clear covering of I
-Helps to refract and focus light
What is the lens
Transparent structure behind pupil
-Refracts and focuses light
What is the pupil
Hole in the centre of Iris
-Controls amount of light entering eye
What is the iris
Pigmented tissue, sphincter
-Controls amount of light entering eye
What are the suspensory ligaments
Ligaments connecting ciliary muscles and the lens
-Involved in controlling accommodation
What is the ciliary muscles
Ring of muscle is connected to lens via suspensory ligaments
-Controls accommodation
What is the retina
Inner layer of eye containing rods and cones
-Responds to stimulus
What is the optic nerve
Sensory nerve (part of CNS) -Carries nerve impulses from retina to brain
What is the retina
The light sensitive inner layer of eye containing photoreceptors
What does a rod do
Dim light vision / light intensity
What does a cone do
Colour vision
- blue
- green
- red
Define accommodation
The reflex that makes the focus on objects by changing its shape of the lens
How do you focus on a far away object
Flatten lens
Distant object in focus
Ciliary muscles relax
Sensory ligaments are pulled tight
How do you focus on a nearby object
Lens rounder
Rays refracted more
Ciliary muscles contract
Sensory ligaments slack
What is the conjunctiva
The layer covering the cornea or sclera
-Helps lubricate the eye
