Oval, square, P3, pantos, octagonal, circle, rectangle, half-eye, rimless, semi-rimless, diamond, laser cut... and the list continues. When it comes to choosing eyewear shape and style, there is an endless number of possibilities for consumers, who ultimately base their decision on fashion. In reality, however, it comes down to far more.

Sure, eyewear is considered a fashion product. But the fact remains that eyewear is also a medical aid, designed to help people see better. So while fashion appeal certainly plays a large role in choosing frame shape and style, it's important to realize that not all frames work with all prescription needs. Making the connection is a common dispensing challenge.

According to most dispensers, the key to successfully matching the frame to the Rx is getting to know your customers before you even think about dispensing any eyewear. Showing customers frames before knowing their lens needs will ultimately lead to disappointment.

To help you successfully match the frame and prescription each time you dispense a pair of eyewear, we asked for tips from several optical professionals -- a frame designer, an optician, a lens vendor, a frame vendor, and a lab representative.

Making the Connection

Regardless of whether a patient has a plus (hyperope) or minus (myope) correction, all of those interviewed agree that one of the biggest concerns, particularly among those with strong Rxs, is lens thickness. Therefore, it's crucial to determine how to provide each patient with the thinnest lens possible (minimum blank size) and pick a frame that hides any additional lens thickness.

Here's what to consider:

Patient PD. How close is the frame PD (pupillary distance) to the patient PD? The closer the better, because it keeps the need for lens decentration to a minimum. This is important because lens decentering significantly increases the edge thickness. Frame shapes that are symmetrical or don't have a longer dimension in any one direction, such as rounds, pantos, ovals, P3s, and soft squares, are perfect for a strong Rx because the frame PD often matches, or comes close to, the patient PD.

Eye size. The smaller the frame eyesize the thinner the lens, certainly in line with the current trend toward small frames.

Extended temples. Small eye sizes are even an option for patients with larger faces since the introduction of extended temples, which expand the size of the frame.

Plastic frames. Heavy zyls help hide thick edges. This is particularly good for myopes because their lenses are thickest on the edges. Laminates -- several layers of  plastic laminated together -- offer consumers another trendy option.

Back mounts. Laser cut metals, which give a flattened appearance, allow for back lens mounts and hide lens edges.

Side shields. Side shields -- a very trendy option available in metals, plastics, and combination styles -- are built into the side of the frame and block lens edges.

Harsh corners. Frames with severe corners, such as octagonals, are growing in demand. While this is a good choice for hyperopes, myopes should avoid them, as they show edge thickness. If a myope insists on a geometric shape, try a softened diamond.

Add-ons. High-index lenses, anti-reflective coatings, edge polishing, and cosmetic tints all help minimize lens thickness.

What's Too Small?

The above frame and lens considerations also apply for dispensing eyewear to presbyopes. But presbyopes present dispensers with additional challenges and considerations when matching frame and Rx. For more and more presbyopes -- especially baby boomers, a generation obsessed with looking young -- progressives (PALs) are the lenses of choice because they are a welcomed alternative to bifocals. For the past several years, the biggest problem has been fitting PALs -- which require enough frame depth to accommodate the various viewing areas -- in today's small, trendy frames. To many, it's like fitting a square peg in a round hole.

The minimum seg height requirement for most PALs is 22mm, according to the OLA, which states that anything less will cut off the reading portion of the lens and compromise the patient's visual acuity.

Lens designers are researching PALs that require shorter depth requirements. At last year's OLA convention, American Optical released its Compact lens -- a progressive designed with smaller frames in mind. And a few other suppliers say some of their existing designs will work with smaller sizes. Multigressiv, Rodenstock's atoric progressive, is one such product that is reportedly designed to maximize vision in smaller frames.

"We don't see fitting small frames with progressives as a problem," says Kirsten Bedard, an optician at Au Courant in Troy, Mich. "The Compact and Multigressiv are great. We fit people with them all the time and we've had no complaints."

Most labs have seen a big increase in orders for PALs in small frames and most of them will fill the prescriptions for PALs in small frames that don't meet depth requirements, but not without warning.

For patients who want a small frame, the experts we interviewed offer some considerations for fitting them with PALs:

Diamond shape. A small, softened diamond is very fashionable and provides more depth than many small shapes.

Consider natural bridge. A patient with a naturally low bridge is a good candidate for the small frame/PAL connection, because he gets more depth than someone whose frames sit high on his face.

Adjust nosepads. Adjust nosepads to lower the bridge, which provides more depth.

Avoid nasal cutouts. Shapes with deep nasal cutouts, such as aviators, cut in the reading portion of the lens.

Mostly metals. Strong metals, particularly titanium, are a great choice for progressives because they hold their shape well.

Rimless options. Tension mounts are a good option for rimless frames, which are growing in popularity, since they hold their shape well.

While making a successful frame and lens connection becomes more challenging as more and more frame shapes and styles hit the market, it's a crucial step in maintaining integrity among your demanding clientele. EB