Question

The polymer used for making contact lenses for eyes is:
A.Polymethylmethacrylate
B.Polyethylene
C.Polyethylacrylate
D.Nylon-6

Answer 1

Hint:To answer this question you must recall various properties and uses of polymers. A polymer is a substance whose molecule is composed of a large number of small molecules or units.

Complete answer:
Contact lenses are made using the polymer Polymethyl Methacrylate which is generally known as PMMA. The lenses made using PMMA are known as hard lenses and were used commonly when first made. Now soft lenses made of polyacrylamide polymer are preferred more than hard lenses.

Thus, the correct answer is A.

Additional Information:
Polymerization can be of two types, namely condensation polymerization and addition polymerization. In the question, we will discuss only addition polymerization:
Addition polymerization is the polymerization that occurs by the simple linking between the monomer units without the formation of any by- products. In other words, it occurs through the coupling of monomers by using their double or triple bonds. An example of addition polymerization is polyethylene made from ethylene monomer units. The double bond in each ethene molecule opens and both the carbon atoms form new carbon- carbon single bonds with two other ethene molecules resulting in the formation of a polyethylene polymer.

Note:
Polymer is a Greek word which means many parts. Polymerization is the process of the combination of relatively small molecules to produce a long chain or a network structure. This large molecule is known as a polymer. The small units that combine and make up a polymer are known as monomers. The monomer units can either all be the same or they might be two or more different compounds.