During middle age, usually beginning in the 40s, people experience blurred vision at near points, such as when reading, sewing or working at the computer.
There’s no getting around it — this happens to 99% of the population at some point in life, even those who have never had a vision problem before.
Currently an estimated 90 million people in the United States either have presbyopia or will develop it by 2014.
Presbyopia Symptoms and Signs
When people develop presbyopia, they find they need to hold books, magazines, newspapers, menus and other reading materials at arm’s length in order to focus properly.
When they perform near work, such as embroidery or handwriting, they may have headaches or eyestrain, or feel fatigued.
What Causes Presbyopia?
Presbyopia is caused by an age-related process. This is different from astigmatism, nearsightedness and farsightedness, which are related to the shape of the eyeball and caused by genetic factors, disease, or trauma.
Presbyopia is generally believed to stem from a gradual loss of flexibility in the crystalline lens inside your eye. These age-related changes occur within the proteins in the lens, making the lens harder and less elastic with the years.
Age-related changes also take place in the muscle fibres surrounding the lens. With less elasticity, the eye has a harder time focusing up close. The focal range is shifted with the near vision range falling outside the rentina.
Spectacles with Bifocal, Multifocal or Reading lenses are the most common correction for presbyopia.
Bifocal means two points of focus: the main part of the spectacle lens contains a prescription for nearsightedness or farsightedness, while the lower portion of the lens holds the stronger near prescription for close work.
Multifocal lenses are similar to bifocal lenses, but they offer a more gradual visual transition between the two prescriptions, with no visible lines between them.
Reading lenses are another choice. Unlike bifocals and Multifocals, which most people wear all day, reading spectacles are typically worn just during close work. If you wear contact lenses, the team at Ezekiel Eyes can prescribe reading spectacles that you wear while your contacts are in.
There are contact lenses for presbyopia, called bifocal contact lenses. You can obtain multifocal contact lenses in rigid gas permeable or soft lens materials.
Another type of contact lens correction for presbyopia is monovision, in which one eye wears a distance prescription, and the other wears a prescription for near vision. The brain learns to favor one eye or the other for different tasks. But while some people are delighted with this solution, others complain of dizziness or nausea, or miss the depth perception they once had.
Because the human lens continues to change as you grow older, your presbyopic prescription will increase over time as well. You can expect your optometrist to prescribe a stronger correction for near work as you need it.