More presbyopic patients select eyeglasses over contact lenses and surgery to improve their vision. Specifically, 74% of patients ages 45 to 54 and about 85% of patients 55 and over wear eyeglasses, according to Jobsons VisionWatch study of approximately 100,000 patients. These patients now have several lens options available to them to improve their presbyopia.

Here, your colleagues discuss why their presbyopic patients prefer progressive addition lenses (PALs), the steps you can take to help your patients achieve the best possible vision with PALs, which PALs to prescribe, how to properly fit patients and tips for prescribing PALs for your patients.

Why PALs?
Most O.D.s agree that PALs are typically a better choice than bifocal or trifocal lenses for presbyopic patients. Additionally, many studies of clinical populations show that presbyopic patients prefer PALs to other lenses, says optometrist James Sheedy of Columbus, Ohio.1-3 This is because patients do not see double images through PALs, as they might looking through the line of a bifocal lens, says Dr. Sheedy. PALs provide a smooth transition among distant, intermediate and near vision, says optometrist Jack Schaeffer, of Birmingham, Ala. A progressive lens is continuous, unlike a bifocal, so its more natural for patients, Dr. Sheedy says.

Another reason why patients prefer PALs over bifocals: improved cosmetic appearance. Bifocals and trifocals conspicuously announce to the public that the wearer is over forty, says optometrist Brian Chou of San Diego. This is something that todays emerging presbyopes wont accept, he says.

Patient Exceptions
Although many patients and O.D.s prefer PALs, not everyone should wear them. Patients who prefer or have a job requiring very wide visual fields may not adapt to PALs. This is because areas of clear distance vision and clear near vision are smaller with PALs than they are with bifocals, Dr. Sheedy says. Other patients who might not adapt to PALs include those who move their eyes a lot instead of their head to look at objects, Dr. Sheedy says. This is because the peripheral areas of PALs have blurred optics, and eye movers look through the periphery more often than head movers, who keep their eyes more focused on the center of the lens, he says.

How to Help Patients Learn to Use PALs
Most patients easily learn to use their PALs, Dr. Schaeffer says. Patients with astigmatism and myopia may even learn to use PALs faster than other patients, Dr. Sheedy says.

Dr. Sheedy offers these tips to help patients adjust to PALs:

Tell patients what to expect. Most patients initially experience blur or a swimming sensation when moving from one area of the lens to another, so tell them to expect this when they begin wearing PALs.

I also tell my patients that its common to temporarily feel disoriented while walking, especially when going up and down stairs, says Dr. Chou.

Tell patients to wear their lenses regularly. Patients need to wear their lenses regularly to learn to use them. Many patients learn to use PALs within the first hour they wear them, but some patients may take a few days to adapt to them.

I encourage my patients to avoid switching between their old and new glasses, so they learn to use their PALs faster, says Dr. Chou.

Prescribing PALs
No single PAL design can offer optimal near, intermediate and distance vision because a PAL is a series of compromises, Dr. Sheedy says. Each PAL excels in one or two areas of vision, so lenses should be selected based on a patients needs, such as computer and desk work or driving, he says.1

Near-variable focus progressives, which are lenses optimized for desk work, are often underprescribed, Dr. Chou says. For example, the Gradal RD (Zeiss) and Access (SOLA) lenses offer much wider viewing areas for computer work and reading than standard PALs. The Gradal RD lens has a computer viewing area that is four times bigger than a standard PAL, and the reading area is twice as big, he says.

However, the larger viewing areas of near-variable progressive lenses is a trade-off because the lenses have no distance prescription, so they are inappropriate for driving and watching TV, Dr. Chou says. (To select the best standard PALs for your patients based on their visual needs, see Ten Great PALs for Patients with One Primary Visual Need.")

Ten Great PALs for Patients with One Primary Visual Need
These lenses were selected for patients with one overriding need (i.e., distance, intermediate or near vision) who are not sensitive to unwanted astigmatism.

Distance Need Intermediate Need Near Need (Fit Height 22) Near Need (Fit height 18)
Percepta (SOLA) Gradal Top (Zeiss)  Piccolo (Shamir)  Piccolo (Shamir)
Image (Younger) Definity (Johnson & Johnson)  VIP (SOLA)  Compact (American Optical)
Genesis (Shamir) AF Mini (Pentax)  SOLAMax (SOLA)  Life XS (Rodenstock)
Super No-line (Essilor)   Navigator Precision (Signet Armolite) Life XS (Rodenstock)  VIP (SOLA)
Outlook (Vision-Ease)    Pro 15 (American Optical) Compact (American Optical) SOLAMax (SOLA)
bActive (American Optical)    Hoyalux Summit ECP (Hoya) Super No-line (Essilor) Outlook (Vision-Ease)
Kodak (Signet Armolite)   Life AT (Rodenstock) Hoyalux GP Wide (Hoya)  Super No-Line (Essilor)
Gradal Top (Zeiss)  SOLAMax (SOLA)  Kodak Precise (Signet Armolite)  Kodak Precise (Signet Armolite)
Natural (Essilor)  bActive (American Optical)  Comfort (Varilux)  Comfort (Varilux)
Definity (Johnson & Johnson) Kodak (Signet Armolite)  Genesis (Shamir)  Genesis (Shamir)
Source: Adapted from Sheedy JE. Progressive addition lensesmatching the specific lens to patient needs. Optometry 2004 Feb;75:83-102.

Now, PALs can also be customized based on patients needs and eye and head movements. The Varilux Ipseo (Essilor) PAL, for example, is customized according to a patients prescription and measurements of habitual eye and head movements. The measurements are taken with the Vision Print System (Essilor) while the patient focuses on an object.

This new individual class of progressives takes prescription customization to the next level, Dr. Chou says. The lenses are designed to provide even better optical quality with minimal adaptation. Although individual progressive lenses are novel by todays standards, look for them to become whats standard and expected in the future, he says.

How to Properly Fit Patients
Patients must be properly fitted in order to experience the best possible vision with PALs, Dr. Sheedy says. A poorly fitted lens can easily undo even the most accurately determined prescription and premium progressive lens, says Dr. Chou. Therefore, to help you or your optician properly fit patients for PALs, Dr. Sheedy suggests you follow these three guidelines:

1. Help the patient select the frame. Make sure that the vertical (B) dimension is large enough. Most PALs require a minimum fitting height of 18. If the fitting height is less than 18, you must select a frame design appropriate for such a short fitting height. Also, if the patient uses a computer frequently, a short fitting height is not recommended. Patients should select a different frame.

2. When measuring the fitting height of the frame, make sure that the patient has a natural, upright position, and that you are level with the patients eyes. The patient should not be leaning toward you across the fitting table.

3. Measure the monocular pupillary distance with a pupillometer twice. If there is any discrepancy in the measurements, continue to measure until you are confident of the result. Obtaining an accurate monocular pupillary distance is very important because measurements that are even 0.5mm off can result in less-than-optimal vision through a PAL.

How to Increase Your Prescriptions
In addition to improving your presbyopic patients vision, in-creased prescriptions of PALs can help you to increase your bottom line. Increasing your prescriptions of PALs might come easy because many of your patients will follow your recommendations. According to the VisionWatch survey, the leading reason why patients bought their specific lenses was because their doctor or retailer recommended them. Dr. Schaeffer suggests the following tips to help increase your PAL prescriptions:

Always have the best products available. Your patients might need premium PALs.

Start with the assumption that all presbyopic patients want to wear PALs.

Train your staff to properly measure, adjust and explain the technology. This can save you time.

Because progressive lenses are more technologically advanced and desirable than bifocals or trifocals, they command a greater premium, says Dr. Chou. Doing whats best for your patients can also benefit the financial health of your practice, he says.

PALs are becoming the standard lenses for presbyopic patients. In the coming years, PALs will become even more customized. An example: Ophthonix is currently developing a wavefront-guided progressive lens that will correct both lower- and higher-order aberrations. Until then, prescribing PALs based on your patients individual needs will lead to their satisfaction and success with with these lenses.

1. Cho MH, Barnette CB, Aiken B, Shipp M. A clinical study of patient acceptance and satisfaction of Varilux Plus and Varilux Infinity lenses. J Am Optom Assoc 1991 Jun;62(6):449-53.
2. Sullivan CM, Fowler CW. Analysis of a progressive addition lens population. Ophthalmic Physiol Opt 1989 Apr;9(2):163-70.
3. Gresset J. Subjective evaluation of a new multi-design progressive lens. J Am Optom Assoc 1991 Sep;62:691-8.

Vol. No: 142:9Issue: 9/15/2005