Post on 13-Feb-2017
transcript
We will look at the following parts:
CORNEA (clear lens in front of eye)
transparent covering of the front of the eye
Allows for the passage of light into the eye and functions as a fixed lens.
PARTS: Cornea (Il-xaydh)
Allows for the passage of light into the eye and it also focuses the light
FUNCTION of Cornea
Pupil size is controlled by iris muscles
PUPIL (black hole)
black hole in iriswhere light enters
PARTS: Pupil (Wiil)
Pupil and Iris
the hole where light enters into the eye
FUNCTION of Pupil
THE EYE: PUPILWhen the eye needs more light to enter (when it is dark), the pupils get larger; allowing more light to enter the eye
THE EYE: PUPILWhen the eye needs less light to enter (when it is very bright), the pupils get smaller; allowing less light to enter the eye
The iris is a colored, circular muscle
IRIS (colored part)
colored part of eye
controls light entering
PARTS: Iris (Kurux)
controls the amount of light entering the eye
FUNCTION of Iris
SCLERA – a tough white skin (made of tissue) that covers all of the eyeball except the cornea.
SCLERA(white part)
whites of the eye
supports eyeball
provides attachment for muscles
PARTS: Sclera
supports eyeball and provides attachment for muscles
FUNCTION of Sclera
LENS (lens behind pupil)
converging lensallows us to see objects
near and far
PARTS: Lens
allows us to see objects near and far
FUNCTION of Lens
RETINAinternal membranecontains light-
receptive cells (rods and cones)
converts light to electrical signals
PARTS: Retina
converts light waves to electrical signals
FUNCTION of Retina
OPTIC NERVETransmits electrical impulses
from retina to the brainBrain takes inverted image
and flips it so we can see
PARTS: Optic Nerve(Dareenwadka aragga
Transmits electrical signals from retina to the brain
FUNCTION of Optic Nerve
EYE LID
EYELASHES
CORNEA
LENSE
PUPIL
IRIS
SCLERA
RETINA
BLOOD VESSELS
OPTIC NERVE
Eye
Eye Parts Eye Parts
1 Cornea(Il-xaydh)Transparent window at the front of the eyeball
Allows for the passage of light into the eye and functions as a fixed lens.
2 Pupil black hole in iris
When the eye needs more light to enter (when it is dark), the pupils get larger; allowing more light to enter the eyeWhen the eye needs less light to enter (when it is very bright), the pupils get smaller; allowing less light to enter the eye
3 IrisThe iris is a coloured, circular muscle
.The hole where light inters into the eye.
4 SCLERA – a tough white skin (made of tissue) that covers all of the eyeball except the cornea.
whites of the eye supports eyeballprovides attachment for muscles
Eye Parts Functions5 LENS
(lens behind pupil) Allow us to see objects near and far
RETINAinternal membrane converts light waves to electrical signals
OPTIC NERVE Transmits electrical signals from retina to the brain
Long sightedness
HYPEROPIA• Far-sightedness• Problem seeing close
objects• Distance between lens
and retina too small• Light focused behind
retina• Corrected with
converging lenses
Far-Sighted (Hyperopia)
Short sightedness
MYOPIA• Near-sightedness• Problem seeing objects
far away• Distance between lens
and retina too large• Light focused in front of
retina• Correct with diverging
lenses
Near-Sighted (Myopia)
1.Which structure regulates the amount of light entering the eye?
A. CorneaB. RetinaC. LensD. Pupil2.Which part of the eye regulates the amount
of light entering the eye?A. IrisB. CorneaC. Lens
3. Which part of your changes its size to control entering light:
A. CorneaB. ScleraC. Pupil4. Which part of the eye carries impulses to brainD. Optic nerveE. RetinaF. PupilG. Lens
5.Which part of your eye contains light receptor cells:
A. PupilB. Retina C. Iris6.What is the most common way to fix
Nearsightedness or Farsightedness?D. Glasses and/or contactsE. Eye patchF. SurgeryG. Eye drop
7. A student is constantly squinting to read the blackboard. What is the most likely problem with their eyes?
A. cataractsB. ConjunctivitisC. FarsightednessD. Nearsightedness
1. What are the main structures of the human eye?
2. What are the functions of the iris and the pupil?