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Dispencing optics
The document provides an overview of optical dispensing. It discusses defining optical dispensing and the steps involved, including frame selection based on facial shape, frame measurements, lens measurements, counseling patients on lens materials and coatings, and the process of fitting lenses into frames which involves marking, cutting, and edging lenses.
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Introduction to optical dispensing, its definition, essential components like frame styles, measurements, and ophthalmic lens fitting.
Defines optical dispensing as a sub-specialty in optometry, detailing procedures from prescription to patient satisfaction.
Guidelines for selecting eyeglass frames based on facial shapes: Oval, Round, Square, Rectangle, Triangle, and Heart.
Introduction of Datum and Boxing systems for accurate frame and lens measurements, with historical context.
Detailed measurements for frames including “A” and “B” measurements, focusing on lens shape dimensions in millimeters.
Essential pre-dispensing measurements: Facial wrap, Pantascopic tilt, Vertex distance, and IPD measurement methods.
Types of PD measurement devices (PD ruler, Pupilometer), methods for accuracy in fitting spectacles.
Counseling on lens materials (glass, plastic, hi-index), lens designs (single vision, bifocals), and essential coatings.
Discusses lens coatings, UV protection, photochromatic lenses, tinted lenses, and their advantages.Steps involved in lens fitting: laying off, cutting, and edging various types of lenses to fit frames.
Detailed processes of lens edging with hand edgers, ensuring proper fit and preparation for the final display.
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Dispencing optics
- 1. OPTICAL DISPENSING Dr SolankiOptometry Department
- 2. Over view •Definition • Frame style/Cosmetic Dispensing • Frame measurement • Spectacles Instrument Accessories • Counselling • Ophthalmic lens fitting
- 3. Definition • An opticaldispensing is sub specialty of optometry which includes all procedures from the time the glass prescription is presented to the optician, till the patients are on with the pair the glasses satisfactorily.
- 4. Frame style/cosmetic dispensing Follow thesesteps to choose a best stylish eyeglass frames.
- 5. Determining facial wrap Broadly, there are six face shapes that we observe around the world. Oval Round Square Rectangle Triangular Heart
- 6. Oval Face shape Ovalface shape is the most common face shape and is considered as an ideal one recommend oversized or rectangular frames
- 7. Round Face shape Roundfaces are usually proportional to width and length that features your full cheeks and a broad forehead. recommended rectangular or angular frames for round face shaped persons.
- 8. Square Face shape •Square faces are characterized by a broad squares forehead and a strong jaw line. • We recommended Round or Oval shaped frame.
- 9. Rectangle face shape •Rectangle faces are regarded as the elongated proportion that means a longer, narrower face and nose, along with the same strong jaw line and squares forehead. • We recommended round or cat eye shaped
- 10. Triangle face shape •Triangle face have a narrow forehead, but wider cheek. • These faces look the best in top heavy styles which help balance out the jaw.
- 11. Heart face shape •Heart shaped faces have a broad forehead and narrow jaw line or small chin. • We recommended deep vertical frame shaped frame.
- 12. Frame Measurements • Datumsystem • Boxing system
- 13. Datum system • Previouslyused system for measuring lenses, was established as a system of reference points for the frames & lenses so that position of lens optical centres & bifocal segment heights would be consistent
- 14. Boxing System • In1962 the optical manufacturers association adopted the boxing system to provide a standard for frame and lens measurement that greatly improved upon the accuracy of previous systems. • The boxing system is based upon the idea of drawing an imaginary box around a lens shape with the box’s sides tangent to the outer most edges of the shape.
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- 17. “A” MESURMENT • Itis measured as the horizontal distance between the furthest temporal and nasal edges lens shape of the box. • This is measured in millimetres
- 18. “B” MESURMENT • Itis measured as the vertical distance between the furthest top and bottom edges lens shape of the box.
- 20. Pre dispensing measurement •Facial wrap • Pantascopic tilt • Vertex distance • IPD measurement PD ruler Pupillometer Pen torch
- 21. • Facial wrap facialwrap the frame fills properly following the curved line of the face. • Pantascopic tilt Pantascopic tilt is the angle between the normal to the temple and frame front. • Vertex distance Vertex distance is the distance between the front of the cornia and back of the lens.
- 22. Spectacles Instrument accessories PD measurementdevices • PD ruler • Pupillometer • Pen torch & marker
- 23. PD Ruler Method •Sit directly opposite the patient (arm’s length) • Position yourself 40cm in front of the patient. • Eyes are level. • Place ruler on the bridge of the patient’s nose • Hold pen torch under your left eye directed at the patient’s RE
- 24. • The dispenseraligns the zero mark of the demo lens with the centre of patient’s pupil. • The PD for distance is read as the mark falling on the left pupil.
- 25. The Pupilometer method •Fast and accurate measurement for monocular and binocular PDs. • The variation between the visual axes and pupil centre.
- 26. Pupilometer • Procedure: Holdthe instrument in both hands and rest the pupilometer on patients face. Ability to vary working distance from 20cm to infinity Internal hairline moved until line and corneal reflection are coincident Corneal reflection typically located nasal to pupil center (2 to 5 )
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- 28. Direct pupillary reflexmarking A pen torch will produce clear corneal reflections. Position yourself 40cm in front of the patient. Eyes are level Hold a pen light under your left eye, aiming the light at the patient’s eye. Mark the patient corneal reflex in marker.
- 29. • Mark thepatient corneal reflex in marker.
- 30. Layout card measurment •Measure monocular PD. The recommended procedure is the use of a pupillometer. • Incorrect PD may cause difficulty in using different zones through the lens.
- 31. Counselling • Lens materials Glass Plastic Hi-index etc Lens Design Single vision Bifocal Executive Progressive etc
- 32. • Lens coating ARC SRC UV OR Polarized • Photo chromatic • Tinted lens
- 33. Lens material Traditionally, peopleused to prefer glass lenses. But they have become less popular now due to the danger of breaking. They are also heavier in weight than alternatives. These days, CR-39 plastic lenses are the preferred material for spectacle lenses. It is safer, cost effective and offers an outstanding optical quality. some people would be satisfied with just that-a cheap good quality lens which can correct vision.
- 34. • People becomemore aware, they’ve started realizing there is more to it than it appears. Like UV protection, even lighter weight,
- 35. Lens Coating • Everygood lens has 3-4 coatings, • Each of a microscopic thickness. • Most common of coatings is for toughening the lenses to make it break-resistant. • Then UV protection coating and Scratch resistant. • Lastly, there is the anti-reflective coating Primarily helps in reducing the effect of reflective light from bright objects such lamps or car headlights at night.
- 36. UV Protection andPolarized lens This is one of the major deciding factors. UV exposure has been clinically proven to be an important cause of cataract because of its oxidative effects on humans.
- 37. Photo chromatic • Amajor breakthrough in the area of absorptive lenses took place in 1964 with the invention of corning’s photo gray photo chromatic. • These lenses darken when exposed to light. • photo chromatics are available in both glass and plastic material.
- 38. Tinted lenses • Atint is usually associated with a certain quantity and depth of color, the depth of color is described as density of lens. • Both glass and plastic lenses can be tinted to achieve the desired color.
- 39. Ophthalmic Lens fitting Layingoff • Before a lens is edged it must be marked so that cylinder axis if any is set according to prescription and its optical centre is in correct position relative to lens shape. • We use a lenso meter to mark three dots indicating optical centre position and the horizontal meridian.
- 40. • These horizontallyplaced dots are used to set the lens on correct axis. • In case of bifocals and trifocal and trifocals the three dots should be parallel to top of the segment.
- 41. Lens cutting • Oncethe lens is layed off it must now be cut into desired shape.
- 42. Edging formers • Shankingtongs were then used to crumble the edge away until it roughly resembles eye shape.
- 43. Lens Edging formers •Flat edge • Bevel edge • Mini bevel edge • Grooved edge
- 44. Flat Edge • Thisis the simple form of edge. • It is mainly used for lenses fitted to rimless mounts or as an intermediate stage in the production of other edge forms.
- 45. Bevel Edge • Thebevel edge is used for lenses to be fitted in shall and full rimmed frames. • To avoid pressure on the peak of bevel and the attendant risk of chipping the lens
- 46. Mini Bevel • Thepeak of a normal bevel lies approximately midway between the two surfaces with strong minus lenses and high cylindrical power.
- 47. Grooved Edge • Itis simply a flat edge with central groove. • Used mainly on lenses fitted to spectacles of the nylon supras or semi rimless types.
- 48. Hand Edgers • Ahand edger is still indispensable piece os equipment although new automatic are being preferred. For starting ensure that the hand edging machine in good working condition. It should be set up with adequate water. Hold the lens is both hands with convex side up. Rest your hands on the dip tray and press the lens against the revolving diamond wheel. Make sure to hold the lens across the wheel and at a slight upward angle. Now slowly rotate the lens passing the grip of lens from hand to hand.
- 49. • After edgingmatch size of edged lens with the frame. The lens is right when the shape is exactly like that of the frame to be fitted. • PHOTO
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