EYE ON EQUIPMENT
Go Gradient!
It's not as hard as it seems
By Susan P. Tarrant

Flip through the catalogs of the fashion-forward frame collections and you'll see an increasingly common design element: Gradient tints on the lenses. Whether they are brown, gray, or the trendy caf� colors, tints that are darker at the top of the lenses and gradually lighten toward the middle or bottom are hot items these days. Are you ready for when your patients ask for them?

Dispensers with in-house lab facilities should not be put off by the idea of doing a more fashionable tint, especially if they are already doing sunwear or other dark tints on lenses, say several experts in the lens dye field.

Easy Does It

"Gradients are super easy," says Tracey Morrison of Invicta Corp., makers of Solera fashion photochromic lenses as well as other optical products. A retail lab should already be set up for tinting lenses before they try to tackle gradients. But making the leap from regular tints to gradients can be a natural progression, says Tim Rivett, manager of BPI, manufacturer of optical tints, chemicals, and instruments. The process is as simple as this (thanks to BPI): n Turn clean lenses upside down in the lens holder. The horizontal axis must remain horizontal, or the lenses will have a slanted look in the frame, and will appear to be improperly tinted n A double gradient is achieved the same way, except that the first gradient is usually from the top of the lens to the center or below, and the lower gradient is from the bottom up.n For other multicolor effects, such as three- and four-colored lenses, first tint the whole lens to the central shade. Then, the top and bottom gradient colors are added to accent the cheek tone. The center colors usually accent that of the eye. This effect can be quite dramatic when done properly.n Lenses should be dyed after they are edged.

Pick a Method

Dispensers have the choice of three ways to process gradients: By hand, via a mechanical attachment, or through a computerized attachment. The least desirable is the hand-tinting method.

"It's just a colossal waste of time to have you or your lab personnel standing there holding lenses in dye for 15 minutes," says Morrison. Applying gradients by hand requires the lab operator to literally dip the lens in and out of the dye unit, moving it up to different levels each time.

Not only is the manual method time consuming (and probably hand-cramping) for a lab operator, it is also a method that requires skill from someone who knows dyes well enough to manipulate the lens by hand. A much-preferred method is the use of a mechanical arm attached to the existing tinting unit. The arm repeatedly dips the lenses into the dye at varying levels for varying times, based on gauges set by the operator. "You just pop the lenses in [the arm] and it does the work," Rivett says.

There are a few advantages and disadvantages to this method. The mechanical attachments are inexpensive, are durable, fast, and are easier to use than the manual method.

There is, however, the possibility of receiving a less-than-smooth gradient, Rivett says. Because most mechanical arms apply gradient tints by holding the lenses in the dye at four different depths, a line will sometimes form between the tint levels. To remove the line, Rivett suggests giving the lens a "fast dip" in a hot neutralizer. A third method of applying gradient tints is very similar to the mechanical arm, except that the arm unit is computerized. Instead of four different dips at four different levels with the mechanical arm, the computerized tint unit performs just one dip, moving the lens to different levels automatically. This is the preferred method of all our experts, and it is also affordable, with prices in the $400 to $500 range, depending on vendor."There's a lot of flexibility with a gradient arm," says Morrison, explaining that it can be set for a 3/4 gradient tint, a 1/2 gradient, or myriad options between.She reminds lab operators to make sure they adjust settings to meet the needs of various frame sizes. "If you're putting the lens in a large frame, you'll get the full gradient effect with, say, the 3/4 setting," she says. "If you're using a small eyesize, you'll need to adjust to a half-gradient to get a 3/4 gradient effect on the lens. That's another reason why these arms are so flexible."

Dye Rules Apply

Although applying gradient tints to lenses is not much more difficult than full tints, it is still vital to be familiar with the general rules of tinting. "You have to understand the importance of consistency of temperature, the age of the dye, the lens material being coated, and the other rules of tinting," Morrison says.The material and coating of the lens figures prominently in the tint equation, with each material accepting dyes at varying speeds. Coatings, especially hard coatings, also affect how the lens accepts a dye.Other rules apply when working with colored tints, especially those that are achieved by mixing color bases. Every manufacturer of dyes will be able to supply their customers with color charts and tinting sheets that will provide other hints and instructions for working with the dyes.

Still not sure that you have the customer base to support an investment in a gradient unit? Consider buying gradient lens blanks. Ask your lab or dye supplier for resources. Wholesale labs or tinting companies are also able to provide custom work on an individual-job basis.

"You don't have to do it in-house," says Morrison. "You have alternatives that will still allow you to offer gradients to your customers."