Presbyopia is a condition that is normal as we age. As a matter of fact, the word presbyopia is the Latin word for "old eyes". When we are young, the lens inside our eye, which is necessary for focusing up close, is very soft and flexible. When we need to look up close, we are able to "flex" our lens in order to focus up close. This process of flexing is referred to as accommodation.
As we age, the lens in our eye becomes increasingly less flexible and our ability to accommodate lessens. By the age of the late 30’s to young 40’s, most people can no longer "flex" enough to see up close. Usually, at first, we just hold our reading material a little further away to see. Those people that have myopia (nearsightedness) can take their glasses off and use their nearsightedness to see up close at this age. Presbyopia occurs also with hyperopia (farsightedness) and with astigmatism.
Sooner or later, virtually everyone needs to get some help with their up close vision. The two main choices are usually bifocals, reading glasses, Shamir™ Office Lenses, or half frame reading glassed. It must be emphasized that presbyopia is a normal aging process and everyone gets it with age.
Bifocals come in many varieties. Most people today choose the no line bifocal however lined bifocals still exist. No line bifocals also have the advantage of having a "built in" trifocal that allows the person to see at an intermediate distance besides seeing up close. Lined trifocals also give up close and intermediate working distances.
The Shamir&trade Office Lens is entirely a no line trifocal/bifocal and is excellent for people that use the eyes at different working distances between one foot and six feet away for extended periods of time. These lenses are ideal for people that use computers, hobbyists, musicians, people that have desk jobs, and for people to read for extended periods of time. The Shamir™ Office Lens has the advantage of a very wide zone of near vision as well as about 5 feet of depth of vision. They help to alleviate eye fatigue, neck and back ache, headaches, tension, the necessity of having to tilt the head up and down as when using a bifocal.