unit 1 history of contact lenses Flashcards
William Feinbloom
1936
- combined PMMA with glass (center)
- large contact lenses
Kevin Tuohy
1948
- credited with the first PMMA corneal contact lenses
-error during the lathing of PMMA scleral lens
haptic and corneal portions separated
Otto Wichterle
1972
- unable to attract support
- conducted experiments in his own house which us when he develped the spin-casting technique
- Soft contact lenses
- HEMA material
Norman Gaylord
1974
- incorporated silicone into the basic PMMA structure
- patented oxygen permeable lenses(GP lenses)
Khls Nilsson
1988
- benefits of 6 month replacement frequency
- gothenburg study proved the benefit of regular lens replacement
Leonardo DaVinci
beginning concepts
- immersing the eye in a bowl of water
Rene Descartes
beginning concepts
- fluif filled tube on the eye
Thomas Young
beginning concepts
- constructed a “fluid-filled eyecup”
Sir John Herschel
1800s
- suggested taking a mold of the cornea and impressing it on some transparent medium
F.A. Muller
1800s
- manufactures of prosthetic eyes
- fitting of a partially transparent shell of thin clear blown glass to a patient
1960s and 1970s
Baush and Lomb
- soft contact lenses commerically in the
USA
- introduced soft contact lenses in 1972
1980s
Toric Soft contact lenses
Silicone lense
- oxygen permeability and extended wear
Bifocal soft contact lenses
- coloured contact lenses
Disposable contact lenses
1990s
1994
Daily disposable contact lenses
- lauched in the UK in 1994
- Johnsone and Johnsone released the
1-Day-Acuvue
1998
Silicone Hydrogel Lenses
- Focus Night and Day (CIBA Vision)
- Purevision (Basush and Lomb)
Soft Lens Manufacture
Lathe cutting
Spin casting
Cast moulding
Lathe cutting
more expensive
custom lenses
- high spherical and/or toric powers,
karatoconus
polymer button
diamond tipped tool
- back surface lathed first
- front surface lathed
Inspection Hydration Re-inspection
inserted into vial
Spin casting
Stainless steel convex tool produced
Plastic concave mould formed
Liquid plastic monomer added to spinning
concave mould
UV radiation to initiate lens polymerization
Edge polished
Inspection Hydration Inspection
Inserted into blister pack containing saline
Autoclaved
Cast Moudling
Stainless steel concave and convex tools produced
Plastic concave and convex moulds formed
Liquid plastic monomer added to concave plastic moulds clipped together
contact lens forms in between moulds
UV radiation to initiate lens polymerization
Inspection Hydration Inspection
Inserted into blister pack containing saline
Do not need to be polisheed
lower cost
efficient
