NARRATOR: Our sensory ability changes throughout our lives. Take eyesight for example. In the first few weeks of life babies can only see about 8 to 12 inches in front of their faces. But their vision improves quickly. And by their first birthday, most babies have 20/20 vision. Our senses continue to develop into young adulthood. Then around age 25 sensory ability begins a slow but steady decline.

DAVID MYERS: Over the lifespan our senses become a little less acute. Vision for example, becomes not quite as sharp, hearing tends to decline, and likewise, the sense of smell and taste, touch even may become a little less acute and sensitive than it was earlier in life.

NARRATOR: The dimming of flavor sensations and a diminished sense of smell and touch can all affect daily life. But for many people, the changes to eyesight and hearing present the most difficult challenges.

DAVID MYERS: Most older people meet vision announcement and they may need extra lighting. They may walk into a room and see a younger person reading under a dim light and think, don't you need more light? Which they do because they're older.

NARRATOR: Diseases like glaucoma and macular degeneration often occur with age. Glaucoma results from damage to the optic nerve, which increases fluid pressure in the eye, causing a loss of peripheral vision. Macular degeneration, typically caused by an accumulation of cellular debris between the two layers of the retina, results in loss of sight in the center of our field of vision.

ELLIOT ARONSON: I had macular degeneration about 15 years ago. I thought I needed glasses for the first time. I went to an ophthalmologist, he took one look at my retina and he said, I'm afraid glasses can't help you. And I gradually saw over the next two or three years my vision slip away. I find a way to work around it. I have a computer that converts the printed word into the spoken word so that I can still continue to write books. It makes life a little more difficult, a little less pleasant. But I can still live a fairly normal.

NARRATOR: Hearing loss is also common among older people.

DAVID MYERS: Hearing loss, like the other senses, tends to accumulate with age. Among people in their mid 70s, about half have a discernible hearing loss. Among those in their mid 80s, 90% have a discernible hearing loss and could benefit from some hearing support. Another consequence of losing hearing is often social isolation. My mother, for example, as her hearing declined and entered deafness really did not enjoy going out to be with other people. Fortunately today the technology enables me to stay connected. If my hearing were to progress to deafness, I also have cochlear implants available as a possible technology to restore hearing, which my mother didn't have.

NARRATOR: Cochlear implants act as prosthetic substitutes for the hair cells in the ear that detect sound which wear down over time. Technological advances have improved the quality of life for many people with diminished vision and hearing. But technology only goes so far. Aging is a part of life. Age also bestows wisdom, confidence, and experience which can help us tackle the sensory challenges ahead.