Presentation on theme: "Spectacle frame Faculty Aravind School of Optometry."— Presentation transcript:
Spectacle frame Faculty Aravind School of Optometry
Spectacle -Definition An optical appliance. Combination of lens and frame front with extended sides. Holds the lenses in the proper position before the eyes.
Frame front Front: portion that contains lens. Bridge: middle area of the two lenses. Eye wire: rim on around the lenses End piece: outer areas of the frame front. Shield: the metal piece to hold the hinge in place
Frame side / Temple Temple: attaches to the frame front and hooks over the ears. Earpiece / Curl: part of temple lies past the temple bend Includes Shaft/Shank, Bend, Shield, Dowel Hole, Butt portion.
Quality plastic materials Nylon - first introduced in the late 1940s - unbreakable, hypoallergenic material. - used for injection-molded sun glasses and men’s frame styles. - because of brittleness and other problems, manufacturers switched to blended nylon. - blended nylon frames are both strong and lightweight. Optyl - a hypoallergenic and light weight material. - maintains its original shape,long time.
Plastic - Drawbacks Easy to break than metal frames. Burn but are not easily ignited. Aging and exposure to sunlight slightly decrease their strength but do not affect color.
Metal frames Monel ( nickel and copper): - strong stable material for making nose pad arms, bridges and end pieces. - the most widely used malleable and corrosion-resistant material. Nickel: strong and generally in making nose pad arms & an allergic to few persons. Nickel-silver : strong rigid material suitable for hinges, end pieces, bridges and decorative rims & becomes brittle. Phosphor-bronze : an alloy comprised mostly of copper. & adjustment is difficult due to the “springy” characteristics of the material. Steel : very strong and thin. - alloy metal comprised of manganese, nickel, iron and chromium.
Costly materials Titanium - a silver-gray metal. - durable, strong and corrosion-resistant. - can be produced in a variety of colors for a clean, modern look with a hint of color. - No allergic to wearers /suitable to all. Aluminum - popular & lighter than titanium and highly corrosion-resistant. - used primarily by high-end eyewear designers because of the unique look it creates. - the most widely used, nonferrous material. - Pure aluminum is actually soft and weak, but commercial aluminum with small amounts of silicon and iron is hard and strong. - rigid material that is difficult to adjust.
Costly materials Beryllium - lower-cost alternative to titanium eyewear - resists corrosion and tarnish. - an excellent choice for wearers who have high skin acidity or spend a good amount of time in or around salt water. - lightweight, very strong, very flexible (making it easy to adjust glasses) - available in a wide range of colors used in making temples with other metals. Cobalt : provides good polish and finish in thin frames and expensive.
Frame Designs Full frame Combination frame Semi-rimless Full rimless (or) Drill mount Half eye
Suitable frame for different faces Oval shape face - Any frame designs Round face - Angular frames Square face - Round / Oval shape Long face & Triangle - Deep vertical frame Inverted triangle designs - Oval / Round diamond face
Frame measurements / Boxing System
Introduction Frame and lens measurements are marked in boxing system. Optical technicians depends the measurements to fit lens accurately. Essential for accurate dispensing to provide the comfort vision with spectacle.
Definition A system based on rectangle formed by the horizontal & vertical lines tangential to the extremes of each lens.
Bridge: Specifications DBL : is a bridge width. Measures between the nasal corner of lens eye wires. Useful to choose the lens blank ( Frame PD/ Geo.Center) is necessary to determine the blank size.)
Lens size measurements Horizontal measurements Measures between the horizontal inside of the eye wires. Add 1mm for the groove of the lens. Vertical measurements Measures between the vertical inside of the eye wires Add 1mm for groove inside of eye wire. Important for OC placement fixing the segment height
F ace measurements An Optician’s ruler is used to take measurements. To select the appropriate size frame. Inaccurate sizes greatly affect the overall cosmetic appearance and comfort ness. To hold the spectacle lens in place.
Face Measurements Monocular PD measurements. Bridge size. Intra temporal distance. Length to bend. Length of drop / angle of ear piece. Pantoscopic tilt. Vertex distance. Segment height.
Segment Height Determines the placement of segment. Measures from deepest portion of the eye wire. SH varies depends on the old spectacle the visual needs in occupational spectacle.
How to locate a segment height? First measure the vertical measurements (VM). (Assume 50mm). Measure Geometrical center = VM / 2. i.e.,50 / 2 = 25 mm Mark 3 mm below Geo.Center for segment height, i.e.,25 – 3 = 22 mm,. Final SH would be around 22mm.
Segment Inset Decide by calculating the total amount of Decentration = (lens size + DBL) – Patient PD
Effective diameter: Specifications Measure from one frame corner to other. Important for selecting the lens/blank size. Min.blank size is determined by adding the ED value with the total decentration + 2mm for edging purpose. Add 1 mm for groove inside the frame.
For the very best fit, think width. That’s right. Top eye experts use width to ensure perfect fit. How? They measure the distance from the hairline of your left temple to the hairline of your right temple and from the left to the right pupil. These measurements are useful for three purposes: - frame selection - lens adaptation - frame and lens final adjustment for optimum comfort Just like when you choose a hat, helmet or shoes, eyewear fit based on your personal measurements is essential for comfort and performance.
Eyewear must be customized. Now, take a look in the mirror to determine the shape of your face. Let eyecare people advise you. There are approximately 5 main face shapes as shown above: oval, round, rectangular, square, and triangular. Once you know your face shape, it is easier to figure out the effect various eyeglass frames will have on your overall look. Try several styles.
You may be surprised what style suits you best! Oval: if you have an oval face, you have the widest range of eyeglass frames to choose from. Large, small, conservative or daring, frames of all kinds can suit you — as long as they are well- fitted! Round: if your face is round, eyeglasses will either accentuate or downplay its shape. Oval or round eyeglasses will tend to make your face look rounder and softer.
Eyeglasses with crisp, straight lines will break up its roundness and give it a more structured, geometric look. Rectangular: smaller frames with a horizontal line tend to emphasize the length of a rectangular face. Bigger, longer frames are more appropriate if you want to make your face appear shorter. Square: if you have a square face, think circles or straight lines. Oval or round glasses will contrast with your face to de-emphasize its squareness. Geometric shapes with straight lines, like squarish, rectangular and triangular glasses will play up your square features. Triangular: if your face is triangular, eyeglasses with pointed angles will bring out the shape of your face more. If it’s a straighter, longer look you are after, you will want to try on some rectangular eyeglasses.