1. Cornea- The clear covering at the front of the eye that lets light rays into the eye

2.  Pupil- A round opening that controls the amount of light entering the inner eye

3.  Iris- The colored circle in the eye that surrounds the pupil and controls its size

4.  Lens- A curved, inner part of the eye; it focuses light on the retina

5. Retina- The light sensitive tissue that lines the inner eye

7.  Optic Nerve-Nerve that takes impulses to the brain

8. Rod- A receptor that is very sensitive to light but can only distinguish black from white

9. Cone- A receptor that can distinguish colors but is not very sensitive to light

10. Nerve Impulse- Electrical signal transmitted along nerves

11. Vitreous Humor- Jelly like fluid in the eyeball

12. Nearsightedness- (Myopia) A condition in which the retina is too far from the lens; A person sees only close objects clearly

13. Farsightedness- (Hyperopia) A condition in which the retina is too close to the lens; a person can see only distance objects clearly

14. Presbyopia- Lens becomes less flexible. Common after the age of 40.

15.  Sclera- The white part of the eye. Composed of tough fibrous tissues that protects the inner layers of the eye.

16. Astigmatism- A condition in which the cornea or the lens is irregularly shaped, causing blurred vision

17. Color Blindness- A hereditary disorder in which a person can not distinguish certain colors

19. Glaucoma- A gradual increase of fluid pressure within the eye; it can damage the retina and lead to blindness

20. Cataract- A condition in which the lens of the eye becomes cloudy. More common among older people

21. Sty- An infection at the base of the eye lash

22.  Conjunctivitis- Caused by a bacterial, virus, or allergic reaction. Primarily because of poor hygiene. Spread by direct contact. (Pink eye)

23. Detached Retina- Occurs when the retina tears away from the inner eyeball, this produces a blind spot around the tear.

24.  Ophthalmologist- eye surgeon  Optometrist- eye doctor  Optician- lens maker