1. Your Eyes and Ears Chapter 13
Personal Care
Your Eyes and Ears
Chapter 13

2. Your Eyes Complex organs that respond to light by sending impulses
Brain interprets these impulses at images

3. The Response of the Eye
When rays of light first strike the eye, they enter through the cornea
Cornea: clear tissue that covers the front of the eye
The light then passes through a chamber filled with liquid that nourishes the eye
Finally, the light enters the pupil
Pupil: opening through which light enters the eye

4. The Iris, Lens, and Retina
The iris is a circular structure that surrounds the pupil and regulates its size
The size of the pupil adjusts based on the amount of light entering the eye
The lens is a flexible structure that focuses the light entering the eye
The retina is a layer of cells that lines the back of the eye

5. Diagram of the Eye

6. Vision Problems
Nearsightedness: can see objects that are close, but not those that are far away
Caused by an elongated eyeball
Farsightedness: can see far away objects, but not those that are close up
Caused by an eyeball that is too short
Astigmatism: distorted vision because images do not focus correctly on the retina
Caused by an uneven curvature in the cornea

7. Nearsightedness

8. Farsightedness

9. Astigmatism

10. Eye Diseases
Optometrist: a professional who provides eye and vision care
Types of diseases that take place in the eyes include:
Glaucoma
Cataracts
Detached Retina
Macular Degeneration

11. Glaucoma
Caused by a slow drainage of the eye, resulting in a build-up of pressure
Can damage the optic nerve and lead to sight problems
Common in people with diabetes and high blood pressure

12. Cataracts
The clouding of the eye’s lens that is common among older adults
Wearing sunglasses with UV protection and not smoking can help slow the development

13. Other Eye Diseases Macular Degeneration Detached Retina
Aging or an injury to the eye can cause the retina to separate from the eye lining
Surgery is the only effective treatment for a detached retina
The leading cause of eyesight problems in older adults
Occurs when cells in the center of the retina break down and become weak

14. Anatomy of the Ear

15. Anatomy of the Ear Outer ear Middle ear Inner ear
Sound enters through the outer ear and reaches the ear drum
Middle ear
Vibrations pass through the middle ear after passing the eardrum
Inner ear
Vibrations in the cochlea cause nerve cells to transmit signals to the brain

16. The Inner Ear and Balance
Semicircular canals
Located above the cochlea in the inner ear
Structures that send information to your brain about the movements of your head
When your head moves, the fluid inside the canals and stimulates nerve cells to keep the body balanced

17. Ear Care Keep the ears clean both inside and out
Avoid loud noises that are directly aimed towards the inside of the ear
Treat ear infections as soon as possible
Consult an audiologist when necessary
Audiologist: professional who is trained to evaluate hearing and treat hearing loss