I am 46, and have nearsightedness and astigmatism in one eye. I've been told by my eye doctors that they would probably undercorrect one of my eyes to enable me to read up close -- in effect, to balance my vision. Right now, I have to take off my glasses to see up close. What is your opinion?

Cindy

By their early 40s, most people lose some of their ability to focus on nearby objects, a condition called presbyopia. This is why many people start to use reading glasses when they reach middle age.

The options for someone with presbyopia are reading glasses, bifocal glasses, bifocal contact lenses or monovision contact lenses. Reading glasses are plus-powered lenses that magnify small objects, like newspaper print. Bifocal glasses and bifocal contact lenses allow a person to clearly see both near and distant objects. In bifocal contacts, the center of the lens is used for distance, and there is also an area that magnifies close objects. Monovision is another method and is only effective with contact lenses (monovision glasses do not work). For monovision, one contact lens is focused for distance and the other contact lens is focused for close objects.

People in your situation -- who have nearsightedeness (myopia) and astigmatism, as well as presbyopia -- can consider all of these choices, including the monovision approach that your doctor suggested. Most people adjust well to monovision, but a few report feeling "unbalanced." Another downside of monovision contacts is a loss of depth perception. However, most people can adapt to this, and will remove the monovision lens when playing sports that require good depth perception, such as tennis or golf.