Common problems:
- Myopia - Near-sightedness - Hard to read signs in the distance.
- Hyperopia - Far-sightedness - Hard to read books, maps, ...
- Astigmatism - Abnormally curvature of the cornea or lens. It makes it difficult to see fine details, either close up or from a distance.
- Presbyopia - A progressively diminished ability to focus on near objects with age.

Age related problems:
- Cataracts - A clouding of the lens in the eye that affects vision. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
- Glaucomia - A group of eye conditions that lead to damage to the optic nerve, the nerve that carries visual information from the eye to the brain.
In many cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP).
- Presbyopia - A progressively diminished ability to focus on near objects with age.

Eye Anatomy:

Source: Medline at nih.gov

Treatments:
Laser In-Situ Keratomileusis (LASIK)
A large percentage of nearsighted, farsighted, and astigmatic patients are potential candidates for LASIK.
See: LASIK Laser Eye Surgery Custom LASIK-Frequently Asked Questions

Glasses:
bifocals, progressive lenses.
Contact lenses:
Contact Lenses - A Consumer Guide from AllAboutVision.com
See eyeglasses in products.

Presbyopia usually occurs beginning at around age 40, when people experience blurred near vision when reading, sewing or working at the computer.
Presbyopia generally is believed to stem from a gradual thickening and loss of flexibility of the natural lens inside your eye.
Bifocals or reading glasses are the most common treatment.
see Presbyopia | What Causes it? | How To Treat It at allaboutvision.com

Links:
Presbyopia and other eye conditions at CataractSurgery.com
Myopia, Hyperopia, Nearsighted, Farsighted, Astigmatism, Presbyopia - What Do They All Mean?
Cataracts / Cataract Surgery, Glaucoma, Presbyopia Ð Monterey, Salinas, Santa Cruz ÐEye Care
Presbyopia | What Causes it? | How To Treat It at allaboutvision.com
California LASIK Surgeon | Eye Care Glossary by a Sacramento
eyeglasses in products.