The lens inside the eye is a marvelous structure. It actually changes its shape when we attempt to see objects close to us. When we focus up close, the lens becomes fatter, and when we gaze into the distance, the lens becomes thinner.
This system works beautifully until we get close to forty or shortly thereafter. Gradually the lens loses its ability to focus (accommodation) and blurred vision for near objects is the result. A slowness in changing focus from near to far may also be noticed. This loss of accommodation is called presbyopia. Presbyopia is derived from presby meaning old, and opia meaning vision. In fact, this is the most predictable, regular, routine age change in the whole human body. Nearsighted patients in this age group may take off their glasses to see up close, and this is one of the advantages to myopia (nearsightedness).
What are the symptoms?
The chief symptom of presbyopia is difficulty in reading. This may be aggravated by reading small print or reading in dim light. Holding the reading matter farther away relieves the strain temporarily, but our arms quickly get too short for comfortable reading.
What are the treatment options?
No treatment, including diet and exercise, can slow down the progression of presbyopia. The best way to correct for presbyopia is with lenses of the proper power to bring things into focus. This can be done in many ways:
- READING GLASSES - These work very well and have the advantage of giving us a full field of vision. When looking into the distance, however, everything appears blurry, necessitating their removal for better distance vision.
- HALF GLASSES - These are the ones Benjamin Franklin made famous. They also provide good near vision, and if the patient has good distance vision unaided by glasses, clear distance vision is obtained by simply looking over the top of the half glasses. Some patients wear these with a chain around their necks.
- BIFOCALS - These are probably the most versatile solution. Good distance vision is obtained through the top part, while clear reading vision is obtained through the bottom part. Curbs, stair steps and objects in our path may be blurred through the bifocal, so some adjustment is necessary when first getting used to them.
- CONTACT LENSES - This can be tricky, but many people find wearing one contact for near and one for far vision is preferable to the other forms of treating presbyopia.