12.1 Dispensing Hand Tools

Ophthalmic Hand Tools in Dispensing

Adjusting and fitting spectacles is both an art and a science, requiring a precise understanding of materials, forces, and specialized hand tools. A professional dispensing optician must be able to select the appropriate tool for a given task and apply the correct amount of force without damaging the frame, stripping screws, or marring the lenses. Ophthalmic hand tools are specialized pliers, files, and thermal devices designed to manipulate metal and plastic frames to match the patient’s facial anatomy.

Key Dispensing Pliers and Adjusting Tools

Each tool in the optician’s dispensing kit serves a specific function. Using the wrong tool can lead to catastrophic frame failure or scratched lenses. Below are the primary hand tools used in daily dispensing:

1. Flat-Round Pliers (also known as chain-nose or half-round pliers): These pliers feature one jaw that is completely flat and another jaw that is round and tapered. They are the workhorse of metal frame adjustments. The flat-round configuration is ideal for bending metal eyewires, temples, and endpieces. When adjusting, the round jaw is placed on the inside of the bend (the concave side) to act as a mandrel, while the flat jaw is placed on the outside (the convex side) to apply the bending force. This prevents the metal from crimping or collapsing at the bend point.
2. Double Nylon Jaw Pliers: These pliers feature replaceable nylon sleeves over both jaws. The soft nylon cushioning is essential for making adjustments to delicate frame materials without scratching, marring, or denting the finish. They are standardly used on high-end metal frames (such as gold-plated or hand-polished titanium), painted frames, and thin plastic eyewires. Opticians use double nylon jaw pliers to adjust the temple spread, pantoscopic angle, or to grip a lens-eyewire boundary securely when adjusting endpieces. Because the nylon jaws wear down or get grooved over time, they must be replaced periodically to maintain their protective qualities.
3. Nosepad Adjusting Pliers: These specialized pliers are designed with a unique slotted jaw that fits perfectly over the metal nosepad box (mounting bracket) and the nosepad itself. Adjusting nosepads requires moving the pad arm in three dimensions to align the splay, frontal, and flare angles. Standard flat-jaw pliers would squeeze the pad and strip the screw or deform the box. Nosepad pliers allow the optician to grasp the nosepad screw box securely and apply leverage to bend the delicate pad arm without putting stress on the solder joint or the nosepad insert.
4. Temple End Adjusters: Also referred to as temple bending pliers or temple styling guides, these tools are designed to manipulate the end tips of temples. They are used to create the mastoid bend (the downward and inward curve of the temple tip behind the ear) or to adjust the wrap of cable temples. Proper temple adjustment prevents the frame from sliding down the nose while avoiding painful pressure points on the mastoid process.
5. Clipping and Cutting Pliers: These are heavy-duty, hardened steel diagonal cutters or end-cutters. They are used to trim excess screw length after replacing a hinge or nosepad screw, or to clip the metal wire core of plastic temples when adjusting temple length. They are also used to cut nylon monofilament support lines in semi-rimless (grooved) frames. Opticians must use flush-cutting pliers to ensure no sharp metal edges are left behind to scratch the patient’s skin.

Thermal Frame Adjusting Tools: Frame Warmers

Plastic frames, primarily made of cellulose acetate (zyl), cellulose propionate, or Optyl, cannot be adjusted cold. Attempting to bend cold plastic will result in stress fractures or a complete break. Opticians use a frame warmer to soften the plastic before making adjustments. There are two primary types of frame warmers:

• Hot Air Frame Warmers: These devices project a stream of heated air through a nozzle. They are clean and allow the optician to target a specific area of the frame (such as a single hinge or temple tip) without heating the entire frame. Most modern warmers have adjustable temperature controls.
• Hot Salt Frame Warmers: These utilize a pan of heated, fine-grain table salt or glass beads. The frame is submerged in the hot medium to distribute heat evenly. While excellent for heating the entire eyewire to insert a lens, salt warmers can leave residue in screw holes and can scratch lenses if salt grains cling to the cloth during wiping.

Different plastic materials react differently to heat. Cellulose acetate (zyl) becomes highly pliable when heated but will bubble, blister, or even ignite if exposed to excessive heat. Optyl, a thermo-elastic epoxy resin, has a shape memory. It must be heated to a high temperature to become pliable. Once adjusted, it must be held in place until it cools, or it will return to its original factory shape. Unlike zyl, Optyl will not burn or bubble easily, but it requires thorough heating to prevent cracking during adjustment.

Adjustment Principles and Hand Tool Safety

When adjusting any frame, the optician must follow three fundamental principles:

1. Isolate the stress: Never apply force across a lens or a solder joint. Always grip the frame on both sides of the point to be bent. For example, when adjusting pantoscopic tilt at the hinge, use one pair of pliers to hold the endpiece steady and another to bend the temple.
2. Support and brace: Use your fingers and hands to support the frame. Hand tools should be used as extensions of your hands, not as blunt instruments.
3. Protect the lenses: Avoid allowing pliers to contact the lens surfaces. Even nylon-jaw pliers can cause crazing (cracking) of anti-reflective (AR) coatings if squeezed too hard against a lens.

Hand Tools Utility Matrix