Millions of people use contact lenses worldwide. They were made to replace glasses and are very useful because sometimes glasses are inconvenient. In sports, for instance, many athletes wear contact lenses instead of using obnoxious sports goggles because they are much safer. Contact lenses can also be used to correct some conditions that glasses are not capable of fixing. People also use them if they want to change the color of their eyes. One can wear contact lenses every day, or they can be used only once, for example, to have red eyes with a vampire costume.
The idea of wearing contact lenses for better vision was first thought of by Leonardo da Vinci in the 1500s. He made sketches but there is no evidence that his design was ever realized. Throughout the 1800s many scientists played with the idea of contact lenses but no one perfected the use of them. The first models were very uncomfortable so they could not be worn for long periods of time. They were not flexible and did not let oxygen get to the eyes so in some cases they caused more problems than they fixed. The earlier versions were also very fragile and expensive, which made them not usable for many people.
It wasn’t until the late 1900s that contact lenses started to be effective and affordable enough for everyone to use. They became more and more popular as people became aware that there was an alternative to wearing glasses. In recent years, people have been developing even more advanced contact lenses. Now they can not only fix poor vision, but can improve good vision. Although contact lenses have become extremely popular over the last few decades, laser technology now allows people to improve their eyesight through a relatively quick, inexpensive, and painless procedure. One day, this technology may phase out contact lenses.
77. The author’s main purpose is to
A. give a brief history of contact lenses
B. persuade readers of the convenience of contact lenses
C. explain how contact lenses improve people’s vision
D. prove the risk of wearing contact lenses for better looks
78. In line 16, the word alternative is closest in meaning to
A. option
B. upgrade
C. solution
D. purchase
79. In line 10, the word They refers to
A. the eyes
B. the scientists
C. the drawings
D. the first models
80. Why does the author mention athletes in the passage?
A. To explain that some sports do not allow glasses
B. To show that athletes are concerned for their health
C. To illustrate the development of today’s contact lenses
D. To give an example of the usefulness of contact lenses
