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Over a four-year period, through the efforts of many scientists and engineers at Vistakon, the company went from making 100,000 lenses a day to 1 million lenses a day—a scale large enough to make disposability a reality.By the time Acuvue disposable soft lenses were launched in 1987, the company’s biggest challenge was probably winning over practitioners, who were reluctant to dispense lenses without verifying the clinical performance of each and every lens on the patient’s eye. Stanley J. Yamane, O.D., F.A.A.O., was one of those recruited to serve on a panel of experts that had early access to the new lenses. “I was initially very skeptical,” he said. “But after three months of dispensing these lenses to my patients and seeing that the reproducibility of the lens parameters, the quality of the lenses and the vision that patients were able to enjoy was exactly as the company claimed, I became one of their strongest advocates.” Dr. Yamane would later serve as Vistakon’s vice president of professional affairs.Once it was proven that disposability could work, other manufacturers rapidly launched their own frequent replacement lenses in the now-familiar blister packs. The concept of disposability was taken even further with the introduction by Vistakon, in 1995, of the first single-use lenses, 1-Day Acuvue.Silicone Hydrogel LensesAs contact lens developers sought to make lenses that would allow more oxygen to reach the cornea, silicone seemed like a natural fit due to its high oxygen transmis-sion and exceptional clarity. Joseph L. Breger, O.D., spent more than a decade, beginning in 1959, trying to make contact lenses from pure silicone elastomer. A 100% silicone lens, the Silsoft lens, was introduced by | 17 Dow Corning in 1981 and is still made by Bausch &Lomb for specialty cases. But, silicone would eventually be successful only in combination with a hydrogel1985Dr. Stone helps craft a new system for classifying lenses according to their polymer properties, making it easier to testnew lens care products for compatibility.material. Silicone is hydrophobic, making comfort and wettability in the eye a challenge. Adhesion of early siliconematerials to the cornea— the “suction cup effect”—was also a major challenge.CIBA Visionintroduced the first successful silicone hydrogel (SiHy) contact lens, the Night & Day lens, to the global market in 1998; it became available in the United States in 2001. “What you need to keep a lens moving on the eye is ion permeability, or the ability for lenses to transport solubilized salt across the lens. That was a key learning,” said Lynn Winterton, Ph.D., a researcher at CIBA Vision in the early days and now the company’s global head of research.Dr. Winterton and other chemists at CIBA Vision, including Tim Grant, O.D., and John McNally, O.D., worked closely with Deborah Sweeney, Ph.D.; Eric Papas, Ph.D.; Lisa Keay, Ph.D.; and others at the CCLRU in Australia to develop the Night & Day and O2Optix (AirOptix) SiHy lenses.
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