Years ago, the introduction of LASIK surgery (Laser In-Situ Keratomileusis ), which is a surgery that improves near-sightedness of human eye, in Korea was a successful business. At first, people were suspicious and afraid of the surgery because eye-surgery at that time was not something popular. People would rather wear glasses than recklessly take an unknown surgery. However, few patients with severe damage of eye sight who had to rely on expensive compact eye lenses took the surgery and improved their eye sight to a point that they could see much better than other ordinary people. People started to pay dollars to get rid of eye glasses or eye lenses, and the LASIK surgery became a popular surgery for teenagers.
However, about ten years later, side effects of LASIK surgery became to appear. Eyes became extremely dry after the surgery and some people even reported that they could only see blurry images. With these side effects evident, a famous TV program summarized the cases and criticized the LASIK surgery.
At first, the few first people who took the surgery showed a high signal of improved eyesight. Although individuals had a low or neutral signal (danger of side effects), they saw the first few successful surgeries and followed their choice of taking the LASIK surgery. This set up a trend, and it became to the public that LASIK surgery has no side effects.
With the discovery of the side effects and the media report of such facts, people found out that the high signal was actually a negative signal. People, all of a sudden, refused to take the LASIK surgery and ophthalmic clinics went out of business because they had no more customers anymore. This time, a negative cascade was set up. People weren’t actually aware of the side effects, but saw other people refusing to take the surgery, and thus follow their choices.