1B3 Sensory System www.juniorscience.ie

1B3 Sensory System OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle www.juniorscience.ie

front view of the eye click for labels “white” pupil iris OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle front view of the eye click for labels “white” iris pupil www.juniorscience.ie

OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle Inside of the eye pupil iris lens optic nerve retina Ciliary muscle cornea www.juniorscience.ie

A B C D E F G can you remember what’s what? CORNEA RETINA PUPIL OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle can you remember what’s what? G A B C D E F G CORNEA CLICK FOR ANSWERS RETINA PUPIL OPTIC NERVE IRIS LENS CILIARY MUSCLE www.juniorscience.ie

OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle light rays the cornea allows light to enter the eye, and refracts (bends) the rays www.juniorscience.ie

the iris contracts and relaxes in response to light conditions… OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle the iris contracts and relaxes in response to light conditions… …this changes the size of the pupil, controlling the amount of light entering the eye… www.juniorscience.ie

OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle the lens focuses light rays to form a clear image on the retina, where sensory cells detect the image www.juniorscience.ie

the optic nerve brings a message to the brain about what we see OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle the optic nerve brings a message to the brain about what we see www.juniorscience.ie

OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle the function of the ciliary muscle is to contract and relax to change the shape of the lens side view lens ciliary muscle l e n s front view www.juniorscience.ie

retina cornea optic nerve pupil iris lens click for answers OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle Choose a name from the list above to match the functions in the table 1. contains sensory cells which detect images 2. contracts and relaxes to change the shape of the lens 3. allows light into the eye and refracts (bends) the rays 4. brings messages to brain about what we are seeing 5. allows light into the inside of the eye 6. contracts and relaxes to change the size of the pupil 7. focuses a clear image on the retina retina ciliary muscle cornea optic nerve pupil iris lens click for answers www.juniorscience.ie

Look at the diagram and explain what is happening OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle Look at the diagram and explain what is happening www.juniorscience.ie

What do you think? Why do we need to blink? Find out what happens to the size of the pupil of your eye (i) in bright light (ii) in dim light ? The eye is round, but the cornea at the front is extra curved. Can you think of a reason for this? www.juniorscience.ie

1B3 Sensory System www.juniorscience.ie