Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Contact lenses

13,527 views

Published on

Contact lens, types, and proper usage and maintenance
Video clips included on proper contact lens care!

Published in: Health & Medicine, Business
  • DOWNLOAD FULL. BOOKS INTO AVAILABLE FORMAT, ......................................................................................................................... ......................................................................................................................... 1.DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Contact lenses

  1. 1. What is a Contact Lens? • Artificial device whose front surface substitutes the antr. surface of the cornea • Used for correction of: 1. Refractive error 2. Irregularities on front surface of cornea
  2. 2. Contact Lens Specifications Diameter 1. Overall diameter (OD) 2. Optic zone diameter (OZ)
  3. 3. Curves • Base curve (BC) or central postr. curve (CPC) • Peripheral curves 1.intermediate (IPC) 2.peripheral (PPC) • Central antr. curve (CAC) or front curve (FC) • Peripheral antr. curve (PAC) • Intermediate antr. curve (IAC)
  4. 4. Edge • Union of the Peri.Postr.C & Peri.Antr.C of the lens Power • Central anterior curve determines the power of the lens • Measured in terms of posterior vertex power in diopters
  5. 5. Thickness • Measured in the centre of the lens • Varies depending upon the postr. vertex power of the lens Tint • Color of the lens
  6. 6. Types of Contact Lenses Hard Lens Rigid Gas Permeable Lens Soft Lens
  7. 7. Hard Lens • From PMMA (polymethylmethacrylate) • High optical quality, stability, light weight, nontoxic, durable & cheap • Diameter of 8.5-10 mm • Disadvantages: 1. restricting the tolerance 2. corneal abrasions 3. stable tear film
  8. 8. Rigid Gas Permeable Lens • Material permeable to oxygen • Hard, but called as semisoft lenses • Manufactured from: 1. Copolymer of PMMA 2. Silicone containing vinyl monomer 3. Cellulose acetate butyrate
  9. 9. Soft Lens • HEMA (hydroxymethymethacrylate) • About 1-2 mm larger than corneal diameter • Advantages: 1. comfortable 2. well tolerated
  10. 10. Soft Lens • Disadvantages: 1. Wettability 2. Proteinaceous deposits 3. Can get torn 4. Limited life 5. Inferior optical quality 6. Increased risk of corneal infections 7. Cannot correct astigmatism > 2D
  11. 11. Soft Lens • Types: ▪ Disposable or Non-Disposable ▪ Clear or Colored ▪ Spherical or Toric ▪ Extended Wear ▪ Multifocal
  12. 12. Spherical Soft Lens • A spherical contact lens is one in which both the inner and outer optical surfaces are portions of a sphere • Corrects both short- and long- sightedness • Cheapest & most comfortable • Easy to get in a disposable form
  13. 13. Toric Soft Lens • A toric lens is one in which either or both of the optical surfaces have the effect of a cylindrical lens, usually in combination with the effect of a spherical lens • Corrects astigmatism • Lens is specially weighted to conform to irregular cornea • More expensive than spherical • Some are available in disposable
  14. 14. Disposable Soft Lens • Daily, two-weekly or monthly replacement • Very simple cleaning (no cleaning for daily) • Latest designs and materials • Very popular
  15. 15. Colored Contact Lens • Handling tint – Useful when inserting or removing lens • Enhancing tint – Makes light coloured eyes more vivid • Opaque tint – Can change colour of eyes
  16. 16. Colored Contact Lens
  17. 17. Extended Wear Contact Lens • New technology • Made from silicone material which transmits oxygen well • Can wear for up to thirty days without removing
  18. 18. MultiFocal Contact Lenses • Can have dual focus lenses • New technology → More expensive • Available as disposable lenses
  19. 19. Indications • Optical • Therapeutic • Preventive • Diagnostic • Operative • Cosmetic • Occupational
  20. 20. Optical Indications • Anisometropia • Unilateral Aphakia • High Myopia • Keratoconus • Irregular Astigmatism
  21. 21. Advantage Over Specs • Can correct irregular astigmatism • Normal field of vision • No aberrations • Binocular vision in high anisometropia • No condensation of rain or fog • Cosmetically more acceptable
  22. 22. Therapeutic Indications • Diseases of Cornea • Diseases of Iris • Glaucoma • Amblyopia • Bandage Soft Contact Lenses
  23. 23. Preventive Indications • Prevention of symblepharon and restoration of fornices in chemical burns • Exposure keratitis • Trichiasis
  24. 24. Diagnostic Indications • Gonioscopy • Electroretinography • Examination of fundus in case of irregular corneal astigmatism • Fundus photography • Goldmann’s 3 mirror examination
  25. 25. Operative Indications • Goniotomy operation for congenital glaucoma • Vitrectomy • Endocular photocoagulation
  26. 26. Cosmetic Indications • Unsightly corneal scars • Ptosis • Cosmetic scleral lenses in phthisis bulbi
  27. 27. Occupational Indications • Sportsmen • Pilots • Actors
  28. 28. ContraIndications • Mental Incompetence/Poor Motivation • Chronic Dacryocystitis • Chronic Blepharitis and Recurrent Styes • Chronic Conjunctivitis • Dry-Eye Syndrome • Corneal Dystrophies and Degenerations • Recurrent diseases like Episcleritis, Scleritis & Iridocyclitis
  29. 29. Hygeine
  30. 30. Complications
  31. 31. The End

×