Techniques to correct vision by cutting microscopic flaps in a cornea to alter its shape were developed by Jose Barraquer inBogotá, Colombia in the 1950s but this technique was not widely used until the 1990s. Why?

a. Lasik surgical techniques were patented and there were legal difficulties preventing their use for forty years.
b. The surgery required the use of diamond knives to make the necessary incisions and were far too precious to use until improvements in the manufacture of artificial diamonds made them inexpensive tools.
c. The technique would need to wait for advances in the use of medical ultraviolet lasers to perform with light a surgery that was too challenging for routine work with a physical scalpel.
d. Communication and sharing of medical techniques and knowledge was very rudimentary in the decades before the Internet afforded ease of information transfer and dissemination