The term presbyopia is Greek, for elderly eye, and is a condition affecting 100% of the population with it’s initial symptoms starting in the early 40’s and slowly progressing until approximately mid 60’s. Presbyopia is the age-related progressive loss of the focusing power of the lens, resulting in difficulty seeing objects close to the eye. While directly related to the lens ability to focus, presbyopia is characterized by an inability to perform the necessary accommodative function needed to see objects close up. In fact, it amounts to a decrease in amplitude of accommodation equal to or less than approximately 3.5 Diopters.

To understand presbyopia one must understand accommodation, or the process by which the eye increases its power to enable clear near vision. To understand accommodation, it is important to compare the eye to that of a camera. In order to take sharp clear pictures, a camera is focused on the targeted object by focusing or moving the lens back and forth. The human eye is different however, in that the lens inside is in fixed position, not able to move back and forth much if at all. Therefore to focus clearly on a near object in the human eye, a change in the shape of the lens occurs to increase its power (thicker and thinner). The extent to which the power of the human lens can change its focus or accommodation is something that decreases in us all with age.

While many conflicting theories exist as to what hampers the eye’s accommodative function, the condition inexorably worsens later in life, making age a primary factor for developing presbyopia. Approximately 40% of the United States population under age 40 wear vision corrective lenses, while greater than 90% over the age of 55 require vision correction including reading glasses, primarily due to the onset of presbyopia. Additionally, the latest Census Bureau forecasts that the number of US Citizens who have the condition is approximately 120 million.

The longest accepted theory on the cause of presbyopia asserts that an individuals inability to focus on near objects with age is the result of a hardening of the lens. The Helmholtz theorizes that presbyopia is caused by the loss of elasticity of the lens capsule or by hardening (sclerosis) of the lens as the eye normally ages. Presbyopia represents a multifactorial, dynamic proces located mainly at the iris lens level inside the eye. The lens is a flexible structure about the size and shape of an M & M candy. Like the cornea, the lens is transparent because it contains no blood vessels. The muscles of the ciliary body make constant adjustments to the shape and thickness of the lens, producing a sharp visual image at all time as the eye shifts focus between near and distance objects.The zonules are the tiny microthin fibers that hold the lens suspended in position and enable it to change shape during accommodation.

Pinpointing presbyopia is a rather straightforward process. Patients suffering from the condition have difficulty reading small print, holding reading material at arms length in order to focus. This condition is also referred to as “short arm syndrome” or “long arm disease”. This arduous and usually futile process produces several symptoms, such as headache, eyestrain, blurry vision, and eye fatigue. Although age is generally the factor most directly associated with developing presbyopia, it seems to become symptomatic earlier in hyperopic individuals.

Optical Correction of Presbyopia

There are several methods for optical correction of presbyopia, including half eye cheaters (drugstore variety), bifocals, trifocals, blended or progressive (no line) bifocals. Available contact lens options are also available, and include multifocal contacts, bifocal contacts, and progressive contacts. Another common contact lens option available to patients includes the monovision contact lens, which produced good near vision in the non-dominant eye.

In patients wearing only reading glasses, the monovision contact lens can often times be worn just on 1 eye. Whereas, patients needing more full time spectacle correction to improve both their distance and near vision, monovision contacts are typically worn in both eyes (1 for distance and 1 for near). Monovision option is nice for patients to explore, as the eye doctor is able to set the patients reading vision at the best level of correction that meets the near vision needs of most of their day. For example, patients who are on computers most of their day have an arms-length focal length that is more desirable for their needs.

Alternatively, patients who instead do a great deal of book reading in a typical day would need a closer near vision focal length. This can be explored with the patient in the comfort of their home, as to which option they prefer most of the time, if necessary. Patients who tend to get ‘car sick’ easily typically don’t tolerate monovision treatment option as well in general. The eye doctor however, is able to ‘tone down’ the degree of correction in many instances, thus allowing better computer and dashboard visual function.

LASIK or PRK eye surgery (Laser Vision Correction Procedures) both serve to correct near vision in one eye and if appropriate, distance vision in the dominant eye. Another surgical option for correction of presbyopia includes monovision cataract surgery, where the surgeon creates reading vision in the non-dominant eye and distance vision in the dominant eye. This simulates monovision as explained above. Cataract surgery can also be done at times in certain settings with multifocal lens implants. This particular treatment option however, doesn’t mean that no glasses will be needed following surgery, and has at times had notable problems postoperatively with night halos and glare.

These particular implants are not typically recommended by Sabates Eye Centers because of high cost and problems as mentioned already. The newest type of lens implant option available for surgical treatment of presbyopia includes the accommodating lens implants. Sabates Eye Centers cataract and refractive surgeons have certified in these newer techniques, and continue to stay in the forefront of this new technology. Cost of these accommodating lens implants remains prohibitive however, as of this writing. Hopefully this technology, in time, will become more affordable and more widely available. Currently, accommodative lens implant technology is not medicare approved, and is typically done only in the non-medicare patient groups having cataract. Another recent surgical option in treatment of presbyopia is a non-laser approach called conductive keratoplasty (CK). Sabates Eye Centers began this surgical approach several years ago, and found that it works best in patients who only wear cheaters and have otherwise excellent distance vision. CK is typically only performed on one eye, the patient’s non-dominant one.

Call the Refractive Coordinator at 913-328-2020 for more information and further discussion of your particular treatment options and pricing issues.

Presbyopia Video Presentations