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Spectacle for computer use

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Occupational Optometry - Computer Vision Syndrome

Occupational Optometry - Computer Vision Syndrome

Published in: Health & Medicine, Business

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  • 1. SPECTACLE FOR COMPUTER USE
  • 2. WHY DO COMPUTERS CAUSE EYE STRAIN ?• Accommodation: Computer use requires focusing & refocusing and eye alignment at 45-75 cm for long time• Vergence: When viewing computer screen, eyes become locked in this close range, increasing near-sightness or myopia• Dry eye: With sustained fixation, the eyes do not blink enough, so they dry out
  • 3. EYE STRAIN DUE TO WRONG MONITOR SETTING FOLLOWING MONITOR SETTING AFFECT EYES• REFRESH RATE refers to how often your monitor redraws the content on the screen 70 hertz or higher is better• RESOLUTION refers to monitors pixel density• The more pixels, the higher the level of detail and less eye strain• DOT PITCH affects the sharpness of the display Lower the number, the sharper the image 0.28 or lower is desirable
  • 4. THE MONITOR VS. PRINTED PAGETHE SIGNAL FROM THEMONITOR IS NOT AS GOODAS THE PRINTED PAGE• A monitor is a dynamic signal, in that screen is constantly being redrawn• A monitor creates images on the basis of varying light intensity through a fixed set of red, green and blue points. This results in less distinct edges, and lower contrast• The illumination of points on a monitor is not sharp, but is somewhat rounded.
  • 5. COMPUTER VISION SYNDROME (CVS) TYPICAL SYMPTOMS• Fatigue• Eyestrain• Headaches• Slow focusing• Tired, burning eyes• Neck and shoulder pain – Frequent bending forward & backward• Blurred vision at distance
  • 6. 9 STEPS TO REDUCE CVS1. Get a computer eye exam2. Use proper lighting3. Minimize glare4. Blink more often5. Take frequent breaks6. Exercise and stretch your eyes7. Adjust the settings of your computer screen8. Modify your workstation9. Use separate eye ware for computer use
  • 7. AVAILABLE CORRECTIVE METHODS1. FULL VISION READING GLASS2. HALF EYE READING GLASS3. TWO SEPARATE SPECTACLE4. BI-FOCAL SPECTACLE5. TRI-FOCAL SPECTACLE6. REGULAR PROGRESSIVE LENSES
  • 8. AVAILABLE CORRECTIVE METHODS 1. Full vision reading glass Full vision reading glass• Clear near vision• Distance blur• Move close to monitor to see clearly.• Need Tint and ARC• Creating neck & back pain and CVS
  • 9. AVAILABLE CORRECTIVE METHODS 2. Half eye reading glass Half eye reading glass• Clear near vision• Distance blur• Must lower heads to an unnatural 15- 45° tilt• Suitable for patients, just becoming presbyopic• Creating neck & back pain and CVS
  • 10. AVAILABLE CORRECTIVE METHODS 3. Two separate spectacle• Clear near vision with reading glass• Clear distance vision with second glass• No Intermediate vision• In-convenient in keeping two spectacle
  • 11. AVAILABLE CORRECTIVE METHODS 4. Bi-focal spectacle• The segment may be too low and set for 30cm• Near vision through lower lens area• Lift their heads by 25°• Visible bi-focal line• Strain in neck and shoulder muscles
  • 12. AVAILABLE CORRECTIVE METHODS 5. Tri-focal spectacle Tri-focal Intermediate vision• Top of the glasses are for distance• Intermediate area for the computer use• Bottom segment for reading and keyboard• Visible tri-focal lines• Inconvenient and Outdated
  • 13. AVAILABLE CORRECTIVE METHODS 6. Regular progressive lenses• Multi focal / Graduated power Design• Lift their heads 25°• The reading area may not be high enough• Intermediate channel is not wide enough – (Hour Glass)• Outside of channel are distorted
  • 14. WHAT ARE COMPUTER EYE WARE ?• They are different from usual glasses• They need special prescription• Using different lens design• Special lens treatments• Optimum visual comfort and work efficiency• Ideal solution for CVS
  • 15. WHO NEED COMPUTER EYE WARE ?INDIVIDUALS WITH THE FOLLOWINGDIAGNOSED CONDITIONS OFTEN REQUIRECOMPUTER GLASSES• PRESBYOPIA• HYPEROPIA• MYOPIA• ASTIGMATISM• HETEROPHORIA• DRY EYE• CONVERGENCE INSUFFICIENCY• DISORDERS OF ACCOMMODATION
  • 16. COMPUTER EYE WARE DIAGNOSTIC INSTRUMENTSThis System simulates the real characteristics of computer screen in the doctors clinic and cause eyes to react the same way as they do when you sit in front of computer in your officeThis allows the doctor to determine the exact correction and prescribe suitable computer eye wareE.g.. PRIO Diagnostic System
  • 17. SIGNIFICANCE OF LENS MATERIAL IN COMPUTER EYE WARE• CROWN GLASS: – Best optics and scratch resistant – Heavy and not safe, therefore not used very much• CR - 39: Standard plastic, excellent optics – Good for small and medium prescriptions• POLYCARBONATE : – Thin, light and strong - Safest lens• HIGH INDEX : – Good for higher prescriptions – Need Scratch resistant and Anti-reflective coatings• PHOTOCHROMIC: – No significance in computer eye ware
  • 18. SIGNIFICANCE OF LENS COATING IN COMPUTER EYE WARE• ULTRA-VIOLET (UV) COATING: – Monitors do not emit UV light – So computer eye ware do not need UV coatings• ANTI-REFLECTIVE COATINGS (ARC): – Reduce reflection and back glare – Available in gold, green and blue color• SCRATCH RESISTANT COATINGS (SRC): – This clear coating hardens to provide a durable, tougher lens – Scratch resistance does not mean scratch proof
  • 19. SIGNIFICANCE OF TINTING IN COMPUTER EYE WARE• THE TINTING: – Recommended for working in a bright lit office – This can cut the amount of light that reaches your eyes and provide relief – But tints and filters dont address the underlying cause of computer eyestrain – Example: Melanin tint• POLARIZATION: – These lenses provide excellent clarity and maximize visual acuity by minimizing glare
  • 20. SPECTACLES FOR COMPUTER USE1. NORMAL VISION SPECTACLE2. COMPUTER READING GLASSES3. OCCUPATIONAL PROGRESSIVE LENSES4. FLIP FOCALS OR CLIP-ON LENSES5. PIN HOLE SPECTACLE6. PC MAGNI VIEWER
  • 21. 1. NORMAL VISION SPECTACLE as computer eye ware• For people with normal vision• Have +0.25 D add power• Idea is not to add magnification• But to move focal point closer without using eye muscles for accommodation• Need ARC and tinting• Rimless frame• Height only 26 mm to permit viewing “underneath” to focus key board etc
  • 22. 2. COMPUTER READING GLASS as computer eye ware• DESIGNED TO SEE AT 45 – 75 CM• ANTI GLARE COATED & TINTED• EFFICIENT PROTECTION & REDUCE EYE STRAINNormal Reading Glass Computer Reading Glass +0.75 to + 2.00D + 1.00 D +2.00 to + 2.50D + 1.25 D +2.50 to + 3.50D + 1.50 D
  • 23. 3a. OCCUPATIONAL PROGRESSIVES as computer eye ware Occupational Progressive• Multi-focal aspheric progressive design for both near and intermediate vision• Lower half for near vision correction• Upper half for mid range vision up to 2.50 M
  • 24. 3b. OCCUPATIONAL PROGRESSIVES as computer eye ware• Wide intermediate area for computer use• Benefit from a natural head and neck position• Ideal solution for CVS AVAILABLE BRANDS:• Power continuously reduced to: AO COMPACT +0.75 D for + 0.75 to + 1.75 NV Zeiss RD +1.25 D for + 2.00 to + 3.00 NV Panorama Mini ESSILOR Kodak Precise
  • 25. 4. FLIP FOCAL SPECTACLE as computer eye wareFLIP FOCALS IS A PAIR OFCLIP-ON ENHANCEMENTS• For Bifocals and progressives• Clip – on half frame glasses• Focus on monitor 45 – 75 cm from eye• Flip down lens for screen viewing• Flip up lens for normal viewing (distance)• Screen park holder, park on monitor• Poly carbonate, simply clip into frames
  • 26. 4. FLIP FOCAL SPECTACLE as computer eye wareFlip Focals Power calculationWORKING DISTANCE CLIP ON READING GLASS 30 – 48” + 1.00 D +0.75 to +2.00 D 24 – 42” + 1.25 D +2.00 to +2.50 D 18 – 36” + 1.50 D +2.50 to +3.50 D - Based on working distance from monitor - Approximately half of reading glass power
  • 27. 5. PIN HOLE SPECTACLE as computer eye ware• Low cost• No glare problem• Increased depth of field• The focusing effort or accommodation is reduced• Good solution for CVS
  • 28. 6. PC MAGNI VIEWER as computer eye ware• Small screens appear much larger, sharper and more distant• Large size and sharpness reduce accommodation problems, so the eye no longer needs to constantly refocus• Distant-appearing text lets your eyes stay parallel, so eye muscles relax• Economically better than buying a large monitor
  • 29. HOW TO CHECK THE QUALITY OF COMPUTER GLASSES ?• The lenses and its material should be of good quality• There should be no aberrations in the lens• Lenses must be centered both vertically and horizontally in front of the eyes• There should be no spaces between the lenses and frame• The lenses should be tilted 15 degrees towards the cheeks• The frame should be slight wrapped to match the contour of the face
  • 30. SELECTION & CARE• Wide choices are available in computer eye ware• Selection depends on occupational conditions, taste, and budget of people• Care must be taken in prescribing the power of computer eye ware• Need special lens design & treatments• Coating and tinting gives good result• Ergonomics is also important