BEST IELTS Academic Reading Test 499

BEST IELTS Academic Reading Test 499

IELTS Academic Reading Test

Contact Lenses

When did people start using them?

It’s probably no surprise that among the sketches of Leonardo da Vinci lies a little diagram of what looks like a modern contact lens on an eye. There seems to be no area that this inventive mind did not venture at some stage, and investigating the anatomy of the eye was one of them.

In his Codex of the Eye, written in 1508, he was actually experimenting with the idea that by immersing the eye (and in this case the whole face) in a bowl of water he could demonstrate how light could be refracted differently onto the eye. The myth that he invented the contact lens started in the 1950’s, probably due to the fact that the image of the spherical bowl could be confused with a drawing of an eye itself.

IELTS Academic Reading Test

Philosopher René Descartes was actually the first to come up with the idea, though still only as a concept. In 1637 he described a water-filled tube with a lens at one end, and the other pressed against the eye. The cornea is the transparent front part of the eye that covers the pupil and iris. It was not very practical as such tubes would need some kind of external support and it would have been impossible to blink.

The concept was not to correct a refractive error (which is when the shape of the eye does not bend light correctly, resulting in a blurred image), which is what contact lenses are used for these days. It was merely to enlarge an image, much like a telescope, though the concept of placing an object on the surface of the eye was certainly new.

IELTS Academic Reading Test

It took another 200 years before English astronomer John Herschel took the next step. Herschel understood that astigmatism was caused by an irregularly shaped cornea and suggested applying a gelatin-filled capsule of glass to the cornea in an article he wrote in 1828. To do this he proposed making a mould of the eye to create the interior curve in the glass. When anaesthesia was developed in 1884, it made it possible to create a mould of the shape of the eye, as Herschel had proposed.

By then there had been advances in precision lens grinding and glass blowing which made it possible to accurately duplicate the shape of the eye using glass. The first usable lenses were not used to correct refraction error, but more serious eye diseases, as they were large and heavy and only tolerable for brief periods.

IELTS Academic Reading Test

A German doctor named A.E. Fick created the first effective contact lens in 1887 that could correct refraction error. Fick developed corneal lenses and also scleral lenses. Corneal lenses only cover the cornea, while scleral lenses extend over the selera, or whites of the eyes. His lenses were effective, but there was still the problem with weight. In 1889, German glass-blower F.A. Muller, improved upon the glass lens by making it thinner and lighter.

Advances in lens making meant that contact lenses started to be manufactured in Germany, Switzerland, and France. These early versions were, however, too uncomfortable to wear for any length of time. They were used for therapeutic purposes, such as extreme distortion of the cornea which could not be corrected with eyeglasses, or when the cornea needed protection from eye infections.

IELTS Academic Reading Test

By the end of the nineteenth century, there had been no further advances in contact lenses. They were available but not widely used. The weight of glass meant that it was difficult to get a small lens to stay in the eye, and larger ones irritated the cornea. Glass is also impermeable, so the flow of oxygen to the cornea was blocked causing further visual impairment. The larger scleral lenses were uncomfortable, irritating, caused swelling and also made the wearer susceptible to eye infections.

They were only able to be worn for short periods, with long resting periods in between. Then there was the added danger of wearing fragile glass in the eye. Using contact lenses simply for vision correction was just not feasible at the time. It would take another 50 years and the arrival of plastics before any more advances could be made.

IELTS Academic Reading Test

American optometrist William Feinbloom designed a glass-plastic contact lens in 1936, which was lighter and more comfortable than the glass version. Things moved quickly from there. In 1938, Americans Obrig and Mullen created the first completely plastic contact lens from Poly(methyl methacrylate) which was extremely light and could be made very thin. Kevin Tuohy, a Californian optician, introduced the first corneal contact lenses in 1948. In 1960, Wichterle and Lima created a plastic lens which was mostly made of water. This new material was hard when dry, yet soft when wet. The lenses made from it were approved for use in 1971, and these are the contact lenses that we wear today.

Do the following statements agree with the information given in Reading Passage 1?

In boxes 1-5 on your answer sheet write

TRUE – if the statement agrees with the information

FALSE – if the statement contradicts the information

NOT GIVEN – if there is no information on this

1. In 1508 Leonardo da Vinci was interested in how the eye was constructed.

2. Leonardo da Vinci came up with the idea of the contact lens.

3. René Descartes experimented on himself with a lens on the end of a tube.

4. Descartes’ invention was meant to correct impaired vision.

5. John Herschel had the idea for contact lenses but did not make any.

IELTS Academic Reading Test

Choose NO MORE THAN THREE WORDS from the passage for each answer.

6. What scientific development allowed a mould to be made of the eye?

7. What was A.E. Fick’s lens used to improve?

8. What was F.A. Muller’s profession?

9. What do we call lenses that extend over the complete surface of the eyes?

IELTS Academic Reading Test

Choose NO MORE THAN ONE WORD from the passage for each answer.

10. The first contact lenses made by a number of companies in Europe only had ……………….. use as they were not practical enough for general purposes.

11. Glass lenses do not allow ………………..  into the cornea and this can make eyesight worse.

12. Not only was plastic safer than having fragile glass pressed against the eye, but the lenses could be made to be very ……………….. so they were not so heavy.

13. The contact lenses that we use today are made of a type of plastic that becomes ……………….. when they come into contact with water.

IELTS Academic Reading Test

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BEST IELTS Academic Reading Test 499

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IELTS Academic Reading Test

1. TRUE

2. FALSE

3. NOT GIVEN

4. FALSE

5. TRUE

6. ANAESTHESIA

7. REFRACTION ERROR

8. [A] GLASS-BLOWER

9. SCLERAL [LENSES]

10. THERAPEUTIC

11. OXYGEN

12. THIN

13. SOFT

IELTS Academic Reading Test

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