Bifocals are eyeglasses that have two different lens magnifications within the same frame, one in the upper half and one in the lower half. This allows for both near and distance vision to be corrected with a single pair of glasses. They were first developed by Benjamin Franklin who got tired of having to switch between two pairs of eyeglasses.
Traditional bifocals have a distinct separation between the two lens prescriptions, with the reading lens usually beginning at the lower eyelid since you typically looks down to read. Bifocals come in a variety of shapes, some with a larger reading area and others with a larger distance area, to suit various lifestyles. For instance, individuals who spend much of their time reading may want a shape in which the lower reading section is larger than someone else who enjoys traveling and may want a larger upper section for distance vision.
What bifocals treat
Bifocals are often used to treat individuals who have presbyopia combined with other vision problems. Presbyopia is a condition in which the eye loses its natural ability to focus on nearby objects, and is common among individuals over the age of 40. Bifocals can also be used to treat children and adults who have trouble focusing on objects up close and experience eye strain when reading.
The major benefit of bifocals is that they offer two different lens prescriptions within a single pair of eyeglasses. This means that an individual only needs to carry one pair of glasses to correct both their reading and distance vision rather than having to constantly switch back and forth between two pairs. Eyeglasses can also be costly, so having to purchase only one pair of glasses can provide a significant cost savings.
While bifocals are practical and convenient they may take some time to get used to. It is not uncommon for new bifocal users to experience headaches, dizziness and eye strain. This is because instead of simply moving the eyes to read or see a nearby object clearly, you may need to move your whole head or the object itself.
Individuals who sit at a computer for long periods of time while wearing bifocals may also experience sore muscles as a result of poor posture from the awkward angles needed to see the monitor clearly.
If you suspect you have presbyopia or find yourself constantly switching back and forth between two pairs of glasses, you may benefit from bifocals. Contact your optometrist today to schedule an appointment and find out if bifocals are right for you.