Making Adjustments
Welcome to our continuing series of Credit Educations Courses for Opticians.
This course has been approved for one hour of credit by the American Board of Opticianry. No fee is required for ABO credit.
Learning Outcomes: At the conclusion of this credit education course, participants should be able to:
1. Identify current frame types and materials.
2. Adjust and fit frames for the best appearance and comfort.
3. Troubleshoot and correct common frame adjustment problems.
4. Understand the synergy between lenses and frames and be able to work with various lens materials and treatments during frame adjustment.
Test procedures: Read the article and then click on the "Take The Test" button at the bottom of the page. This will open a new window with a test consisting of 20 questions. To receive ABO continuing education credit, respondents must correctly answer 16 of 20 test questions. Simply click on the best answer for each question and click the submit button at the end of the test. Your test answers will be automatically sent to Seiko Optical and we will send your CEC or notify you of test failure within 7 to 10 business days.
Note: Some states do not accept home study courses for continuing education credit. Check with the licensing board in your state to see if this course qualifies.
Making Adjustments: Working with Today's Technology for the Perfect Frame Fit
Each frame material has its own unique characteristics, being aware of how to work with them is critical to proper eyewear adjustments and fitting.
Metals
Aluminum: Aluminum is lightweight and durable, and can be anodized for multiple color variations. Aluminum is corrosion-resistant, retains luster, and is lightweight and comfortable to wear. Adjusting aluminum frames can be challenging, since aluminum resists bending. In order to maintain frame color integrity and avoid scratches, always use padded pliers when adjusting aluminum. Aluminum resists soldering, so aluminum frame pad arms and hinges are attached in ways other than by solder. Typically, these joints are riveted or screwed in place, so have screwdrivers and rivet tools handy.
Beryllium: Beryllium-copper alloy creates frames that are corrosion-resistant and lightweight. Because colors become part of the material, they are less likely to wear and fade over time. Beryllium has a high tensile strength, yet is flexible for easy adjustments.
Cobalt: A tough material, cobalt is used in a pure form in frame construction. Cobalt takes colors and enamels easily, allowing designers to create unique shades and hues. Durable, abrasion-resistant, and strong, cobalt can pose adjusting difficulties due to that inherent strength. For consistent adjustments, use two pliers, one for holding and one for adjusting.
Gold, Gold-Filled, and Gold-Plated: Solid gold frames are usually constructed with an alloy such as nickel or copper to help them maintain durability and strength. For example, only half the material is pure gold in a 12-karat gold frame. Gold frame colors vary depending on the alloy used. To protect the finish, always use padded pliers when adjusting solid gold frames and remember to be gentle, since solid gold can be softer than other metals to work with.
Gold-filled frames consist of base metal wrapped in gold alloy. Gold plated or gold overlay frames are constructed in the same way as gold-filled frames, but offer less gold content than gold-filled frames. Gold-plated frames are base metal coated with a thin layer of gold alloy using an electrolytic process. Gold-filled and plated frames offer the luxe appearance of gold but are less expensive. These frames are also durable. However, if the outer gold layer wears off the inner base, metal will show.
Memory Metals: When titanium is combined with nickel and other metal alloys, it results in memory metal. These highly flexible yet strong and lightweight frames return to their original shape after even severe twisting or bending. Careful attention to detail combined with the right tools will help adjust memory metals. Take time and utilize gripping pliers and padded pliers so as not to mar the frame surface, then apply even, steady pressure in the direction needed until the piece is in place.
Monel: The most common metal used in frame manufacturing today, Monel is a metal alloy of nickel and copper and sometimes other metals. It is often used in metal bridges, full frames, and end-pieces for stability and strength. When palladium or nickel-free plating are used, Monel frames are easier to adjust, hold their adjustments, and are more corrosion-resistant. Since it can be coated and colored, Monel is available in a variety of designs. Use standard tools for metal frame adjustments.
Nickel: Nickel is used in combination with other metals to make frames more durable and cost-efficient. In full frame construction, nickel silver is typically a combination of copper, nickel, and zinc, but no pure silver. For hinges, end-pieces, and trim-pieces, less copper and more zinc adds strength. When adjusting frames and frame parts with more zinc, use two pliers--one for holding and one for adjustments.
Silver: Pure silver or sterling silver frames are considered a specialty item, since silver doesn't wear well or comfortably. Occasionally, silver is used as a trace element alloy in frame construction. More often, silver is used as a design accent.
Stainless Steel: Pure stainless steel is non-corrosive and strong. Usually, stainless steel is a mixture of iron and chromium or other elements and can be somewhat flexible in thinner frame designs. Stainless steel frames can be challenging to adjust because of their combination of strength and flexibility, and frame fronts can be difficult to bend to match high base curve lenses. Use padded pliers designed to adjust frame fronts and utilize aspheric/atoric lens technology with flatter base curves for the best lens fit and appearance.
Ticral: An alloy of titanium, copper, and chrome, Ticral is hypoallergenic and durable. Ticral is commonly produced in thicker frame styles than titanium, but is still lightweight.
Titanium: Pure titanium is strong, lightweight, corrosion-resistant, and hypoallergenic. Titanium comes in its pure form and is also used as an alloy with other metals, such as nickel and copper. Premium titanium frame construction can include 99.5 percent titanium with 0.5 percent oxygen and nitrogen, or 74 percent titanium, 4 percent aluminum, and 22 percent vanadium, which creates a flexible titanium-based material.
More Metal Frame Adjustment Tips
Best Tools: Gear up your metal frame adjustment arsenal with flat-round jawed pliers, pad-angling pliers, snipe-nose pliers and/or end-piece adjusting pliers, and a multiple-head screwdriver.
Face-Form: To change the degree of face form on a metal frame, use two pairs of padded pliers to grip the bridge near each eyewire, then rotate the pliers in opposite directions in order to increase/decrease bridge curvature.
Nosepads: Nosepads should be adjusted so that no part of the eyewire touches the face, and the pads should rest on the bony part of the nose. Nosepads should rest flatly and sit evenly on the nose. Keep a well-sharpened screwdriver with multiple heads handy for working with nosepad screws. Use snipe-nose pliers to move the guard arms to equal heights. Use flat-round jawed pliers to equalize the bend by shaping it around the pliers' round jaw.
Use pad-angling pliers to angle nosepads so that they mirror the shape of the nose. Bend the frontal angle so the pads are narrower at the top. Angle the front edges of the pads inward toward the bridge to create a splay angle.
Nosepads should be perpendicular to the floor. The bottom of the pads should be angled closer to the eyewire than the top for the best vertical angle. Properly adjusted nosepads rock into place on the nose.
Pantoscopic/Retroscopic Tilt: Tilt frames toward the cheeks (panto) or the eyebrow (retro) by using end-piece adjusting pliers. Standard alignment calls for a pantoscopic tilt of 12 to 15mm, or a 90 degree angle at the endpieces.
Rimless: Many metal frame techniques apply to rimless mounts as well. Remember that lenses in rimless eyewear are more vulnerable, which means more of a chance for scratched or damaged lenses. Three-piece bracing pliers with nylon pads help grip and buffer adjustments to protect lenses. Adjust rimless frames in the most stable part, close to the drill holes, using bracing pliers before bending. Whenever possible, protect and cushion lenses with a cloth or soft tissue before adjusting the frame. Ask frame manufacturers about tools made exclusively to work with their rimless designs, and be sure to have plenty of spare parts such as temple clips, compression bushings, screws, and nuts and bolts on hand.
Screws: Look for screws that feature anti-slip sleeves that are self-locking, which help prevent screw back out, loss, and constant adjustments. Be sure to have a multi-head screwdriver on-hand to handle all types of screws. Washers secured in hinges are a premium construction bonus.
Temples: To accomplish an around the ear temple bend, heat evenly and carefully using a bead/salt pad, then bend using the support of hands, especially thumbs. Use padded pliers to adjust temple width and vertex distance/angle. If the temple tips are covered by non-standard material, such as rubber, heat is generally not required for adjustment; check with the frame manufacturer for proper procedures.
Unbreakable? No frame is unbreakable. Solder points, nosepads, and joints are especially vulnerable to breakage, even with advertised "unbreakable" frame materials. Always use care and the right tools when adjusting any frame, and be especially aware of a frame's weak points.
PLASTICS
Carbon Fiber: Strong, durable, and lightweight, CF frames consist of carbon fibers blended with nylon and plastic. Most CF frames utilize metal temples and/or end-pieces to make adjustments easier, since this material is highly heat-resistant and can be brittle when cold. Padded, needle-nosed pliers may be used to help narrow or widen end-pieces and a screwdriver will be needed for nosepads and temple screws, similar to a metal frame adjustment. Select aspheric/atoric lenses in a flat base curve for the best fit, since customized frame front curvature is difficult to achieve when adjusting.
Cellulose Acetate: CA or zylonite/zyl is the most commonly used plastic frame material. It is used for safety frames and is a non-flammable material. New CA frame designs are thinner and smaller. Constructed of plastic, fibers, and stabilizers, CA is pliable for accommodating adjustments and lens size and is available in a wide array of colors. CA is heavier in weight than newer plastic materials, and can experience color-fade and brittleness over time. Use caution when adjusting CA frames, since they can be easily overheated, especially darker colors. For the best results when heating, use a hot-air blower rather than a salt/bean pan whenever possible. Smaller, thinner CA materials may require slightly more heat when adjusting.
Cellulose Propionate: A nylon-based plastic, CP is similar to CA in make-up, but CP is manufactured by injection molding rather than block sheet milling. CP is lighter weight than CA and the molding process can produce hypoallergenic, thinner, more detailed frames. Use caution when adjusting CP frames, since they're highly heat-sensitive and can stretch with no rebound. Don't use rubbing alcohol or acetone on CP frames, as they can fade and discolor CP material.
Memory Plastics: Optyl, a combination of epoxy resin and hardening agents, is brittle when cold and returns to its original shape when carefully heated. Optyl is hypoallergenic and retains its luster. It is crucial to heat only the part of the Optyl frame that's being adjusted, and then hold it in place while cooling. Underheating can cause Optyl frames to snap; overheating can cause Optyl frames to warp.
Microcrystalline polyamide, another memory plastic, is flexible and retains shape after bending, holding adjustments well. Utilize medium heat around the targeted adjustment area, adjust, and then hold in place until the area cools.
Nylon and Blended-Nylon: Nylon is hypoallergenic, highly flexible, lightweight, and heavy-duty durable. Nylon and blended-nylon are the primary materials used in sport and safety frames. Nylon typically requires high, focused heat to adjust. All of your adjustments should be held in place until the frame cools.
Polyamide, co-polyamide, and grilamid frames consist of a blend of nylon-based materials. These materials are strong, flexible, hold shape, and resist color fading. Typically, blended-nylon products require low heat for adjustments. Resist using rubbing alcohol and acetone on nylon and blended-nylon frames.
Polycarbonate: In addition to its popular use in ophthalmic lenses, polycarbonate is also used in safety and sports frames. Ultra-tough and lightweight, poly frames are tough to adjust. Because the material is so durable, it doesn't take colors easily and is seen primarily in clear sports frames with bridge inserts and sports straps to hold the frames in place.
Lenses must be cut to exact size for insertion, since poly is non-malleable. Just as with poly lenses, rubbing alcohol and acetone are not recommended for use on poly frames.
Wood, Horn, and Bone: Frames of wood, horn, and bone are unique, handmade creations. These materials are stiff and not prone to easy adjusting, so getting a correct fit from the start is crucial.
More Plastic Frame Adjustment Tips
Salt/Bead Pan: Always start by stirring the salt/beads. Some ECPs sprinkle talcum powder in the salt/bead pan to keep the contents from sticking together.
Next, push the salt/beads into a mound, usually in the center of the pan. Then, place the section of the frame to be heated just beneath the surface and move the frame slowly and continually to avoid pocking the frame. Heated frames should not become distorted or rubbery.
Pantoscopic/retroscopic tilt: Adjust panto or retro from the hinge piece where the frame front and temple meet. Angling the frame front down creates pantoscopic tilt; angling the frame front up creates retroscopic tilt. The standard adjustment calls for pantoscopic tilt between 12 and 15 degrees.
Specialty Materials: Specialty frame materials may call for unique adjustment methods, since some materials heat more quickly or slowly than standard, and some materials are more flexible or rigid. With these materials, always follow frame manufacturer instructions.
Temples: Heat carefully under medium to low heat in a salt/bean pan or hot-air blower at the desired behind-the-ear bend location. Support the bend with fingers from both hands, primarily using the thumb. Open temple angle should be between 90 and 95-degrees.
Library temples typically rely on a strategic bend behind the ears to help hold frames in place, while skull temples, popular on many of today's sport-and-sunwear styles, rely on pressure to keep frames in place. Cable temples are flexible and wrap almost entirely around the ear. Proper frame adjustment is achieved when there is equal balance between the nose and ears.
Face Form: Heat plastic frames to recommended temperatures and create face form evenly using even hand pressure to curve the frame to match face contour. If unsure of the material type, always start with low heat.
Practice adjustment techniques often, watch and learn tips, techniques, and tricks from other ECPs, and always check with frame and lens manufacturers on their recommended best ways to work with their products.
This concludes the article. Click the button below to take the test.