 The information from different senses goes to different parts of the brain.

 80% of the information comes from the eyes.  The eyes allow us to see because of LIGHT and the BRAIN.  f3s&feature=related f3s&feature=related  Up to 1:40 (reflected light, rods and cones)

 Sclera ◦ Rigid ◦ Opaque ◦ 1 mm thick ◦ Protects eye ◦ Gives it shape ◦ (white of the eye)

 Cornea ◦ Dome shaped ◦ Clear ◦ Rigid ◦ Extension of the scelera

 Choroid ◦ Middle layer ◦ Contains blood vessels that nourish eye

 Yk&feature=related Yk&feature=related  Cross section of an eyeball

 Iris ◦ Extension of the choroid ◦ Coloured part of the eye ◦ Has an opening (the pupil) that regulates the amount of light coming into the eye.

 The pupil is a black hole.  When the amount of light changes, the IRIS changes size.

 Retina ◦ Thin beige layer at the back of the eye ◦ Covered with millions of light-sensitive nerve cells that transform incoming information into nerve impulses.

 eo&feature=related

 Retina…  Specialized light-sensitive neurons ◦ Rods  Night vision  Shapes and sizes ◦ Cones  Details  Colours

 Optic Nerve ◦ transmits visual ◦ information from ◦ the retina to the ◦ brain.

 Blind spot ◦ The junction point between the optic nerve and the retina - has no sensitivity to light. *test for blind spot*

 Lens ◦ Flattened sphere ◦ Focuses light rays on the retina Held in place by muscles that can change its shape (and focus)

 Near object – ◦ Lens becomes thicker and shorter  Far object – ◦ Lens becomes thinner and longer ◦ Usually in this position ◦ ature=related

 Aqueous Humour ◦ Transparent liquid ◦ Fills the space between the cornea and the lens

 Vitreous Humour ◦ Transparent ◦ Jelly-like ◦ Fills the space between the lens and the retina

 Transparent membranesMembranes ◦ Cornea Scelera ◦ Aqueous humour Choroid ◦ Lens Retina ◦ Vitreous humour ◦ Allow light to pass through them to reach retina

 Eyes  Brain  Light  Optic nerve  Parts from above

 Because your eyes are essential for your survival, they are well protected.  Eye Socket 1. The eyeball is located in a hollow  part of the skull, it is called the  eye socket. The bones that encircle  the eye helps protect it from  large objects.

 2. The eyelids are very thin layers of skin that can shut out light and protect your eyes from damage.

3. The eyebrows are short hair that help prevent falling dust and perspiration from entering your eye.

 4. The eyelashes at the edge of the eyelids also protect your eye, they form a fine screen that traps small particles before they touch the eye.

 5. Tear glands are located above each eye socket. They produce a watery, salty liquid that flows onto the eyes to keep them moist and wash away particles that touched the surface of the eye.

 Even with these defenses, your eyes are not safe from all harm. It is important to wear proper eye protection such as: sunglasses, goggles, special eye equipment so that the cornea, lens and retina are not damaged.