What is Presbyopia?
Presbyopia is an age-related progressive reduction of the eye’s ability to focus on nearby objects. Presbyopia is a normal and often irritating part of the aging process that typically becomes perceptible in a person’s early to mid-40s and keeps deteriorating until about age 65. A simple eye exam can verify presbyopia, which cannot be avoided by even those who have never experienced eye problems before. Even people who are near-sited, may eventually notice a blurring in their near vision, when wearing their contact lenses or glasses to adjust for distance vision.
Overall, there is a heightened and growing number of older citizens in the U.S.,resulting in a large demand for contact lenses, eyewear, and surgery to help presbyopes manage and treat their declining near vision. According to the World Health Organization, over one billion people in the world had presbyopia as of 2005, and 517 million of these people did not have sufficient correction.
What Causes Presbyopia?
Presbyopia is generally thought to result from a natural aging process characterized by a gradual thickening and decrease in flexibility of the natural lens inside the eye. This age-associated process takes place within the proteins of the lens, causing the lens to stiffen and become less elastic over time. Age-related changes also occur in the muscle fibers that encircle the lens, and with diminished elasticity, the lens can no longer change shape and experiences more difficulty focusing up close.
Signs and Symptoms of Presbyopia
As presbyopia gradually occurs, a person may notice these signs and symptoms after age 40:
- Inclination to hold reading materials at arm’s length to make the letters clearer.
- Blurred vision at standard reading distance.
- Headaches, eye strain, or fatigue after doing close up work or reading.
- Squinting when reading.
These symptoms may become worse if a person reads or does close up work while tired, with alcohol in their system, or in dim lighting.
When to Visit an Eye Doctor
When a person is experiencing trouble reading or doing close work, or if blurred close-up vision is holding a person back from enjoying their normal everyday activities, a visit to the eye doctor can be very beneficial. The eye doctor can diagnose whether the person has presbyopia with a simple eye exam and will discuss their treatment options if necessary.
Presbyopia Treatment Options
In the past, presbyobia was always corrected with bifocal lenses, but currently there are many options for treating the condition including contact lenses, eyeglasses, and surgery. As presbyopia causes the lens of the eye to keep changing over time, a patient may intermittently require a stronger correction prescription. Regular eye exams will guarantee that a patient’s prescription is optimized for them to experience the best possible vision.
Contact Lenses for Presbyopia:
- Bifocal contact lenses—These are available in both gas permeable lenses and soft lenses. Bifocal contacts contain two prescriptive powers, one for distance and one for near vision.
- Multifocal contact lenses—These are available in both gas permeable lenses and soft lenses. Multifocal lenses contain variations in power to help near, intermediate, and far vision.
- Monovision lenses—For this type of presbyopia correction, the patient wears a prescription for distance vision in one eye and near vision in the other eye. The brain assimilates to favor one eye or the other for different tasks. Some people prefer this option, while others experience and complain of a decreased visual acuity and depth perception with monovision.
- Distance lenses—These can be worn in both eyes, and the patient will wear reading glasses over them for close up work.
Eyeglasses for Presbyopia
The two most common forms of treatment for presbyopia are:
- Bifocal eyeglasses—With bifocal lenses, there are two points of focus. The main portion of the lens has a prescription for distance vision, and the lower part of the lens has a different prescription for near vision and close up work.
- Progressive eyeglasses—Progressive lenses are much like bifocal lenses, except they provide a more continuous and gradual shift from one prescription to the other. There is no visible line between the prescription for distance vision and the prescription for near vision.
Reading glasses are also an option for treating presbyopia, and they are typically worn when doing close-up work only. If the patient normally wears contact lenses, the eye doctor may also prescribe reading glasses to be worn over contact lenses. Over-the-counter reading glasses or prescribed reading glasses may both be options.
Surgery for Presbyopia
LASIK Vision Correction Surgery and Conductive Keratoplasty (CK) Surgery are surgical treatments for Presbyopia.
LASIK Vision Correction Surgery
This is an option for achieving monovision (described above). LASIK is the most commonly performed type of refractive surgery, which means the shape of the dome-shaped clear tissue (cornea) at the front of the eye is changed. An ophthalmic surgeon performs LASIK surgery which, in simple terms, involves reshaping the cornea with a laser.
Conductive Keratoplasty (CK) Surgery
This is also an option for achieving monovision (described above). For Conductive Keratoplasty (CK) surgery, an ophthalmic surgeon specifically uses radio waves to reshape the surface of the cornea; the effect, however, is not permanent.
Several other surgical options for correcting presbyopia are awaiting FDA approval and undergoing clinical trials.