Some things are designed to withstand the test of time, improving with age. Unfortunately, the human body does not always follow this pattern. Specifically, eyesight tends to worsen as you age. Some people find it more difficult to see faraway objects, while others have trouble seeing close objects clearly. Whether you are near-sighted (myopia) or far-sighted (hyperopia), it is likely that you will also develop presbyopia by the time you turn 50.
Presbyopia is an optical condition that occurs when the lens of the eye loses flexibility. As the lens becomes more rigid, it becomes more difficult for it to bend and flex as needed. Flexibility of the lens is what allows the eye to shift focus between objects at different distances. Eye muscles contract and relax, which causes the lens to change shape and bring objects into focus.
Symptoms of Presbyopia
As people reach their 40s, the lens begins to harden. Objects once viewed clearly at close range become blurrier because the eye cannot focus properly. People with presbyopia often need to hold closely viewed objects such as a phone, book, or restaurant menu further away from their eyes in order to bring the object into focus. If they wear glasses, they may need to remove them to read or see objects close to their face.
After presbyopia sets in, it will gradually get worse until it levels off around age 65. Fortunately, it does not lead to a total loss of vision and can be corrected by wearing bifocal lenses as prescribed by an optometrist. Bifocals have a second lens with a different level of magnification that makes up part of the main lens of the eyeglasses. This portion allows the wearer to see close-up objects clearly — ones that their eyes would otherwise be unable to focus on.
Getting a Good Fit
Wearing bifocals can be disorienting at first, and it may take time to adjust to them. Bifocals are less effective if the frames are too small or do not fit properly on the face. Frames for bifocals must be able to accommodate lenses that are a minimum of 27 to 28 millimeters. The frames also need to be adjusted carefully so the magnified area of the lens is positioned properly in front of the eye. Adjusting the temple arms to fit closely to the head and ears — and the nose pads, if present, to the bridge of the nose — ensures a snug, comfortable fit that allows the patient to easily use both parts of the bifocal lenses.