Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q17 (CDS-I/2011) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Applied everyday chemistry Answer Verified

Contact lenses are made from

Result
Your answer: —  Â·  Correct: C
Explanation

Contact lenses are primarily made from polymethyl methacrylate (PMMA), a transparent thermoplastic [1]. PMMA is widely known by various trade names, including Lucite, Plexiglas, and Perspex. Historically, PMMA was the standard material for 'hard' contact lenses because it served as an eye-friendly, shatter-resistant alternative to glass. While modern advancements have introduced soft hydrogel and silicone hydrogel materials to improve oxygen permeability, PMMA remains a foundational material in the history and production of rigid lenses [2]. In medical applications, Lucite (PMMA) is valued for its optical clarity and biocompatibility, making it suitable for replacing eye lenses and creating durable contact lenses. Other options like polyvinyl chloride (PVC), polystyrene, and Teflon (PTFE) are industrial polymers used for pipes, packaging, or non-stick coatings rather than corrective optical lenses.

Sources

  1. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC6356913/
  2. [2] https://openaccess.city.ac.uk/id/eprint/13791/1/Koller,%20%20A.W..pdf
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
25%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

CDS-I · 2012 · Q51 Relevance score: -1.11

Which one among the following polymers is used for making bullet-proof material ?

IAS · 1995 · Q101 Relevance score: -2.88

Which one of the following polymers is widely used for making bullet proof material ?

CAPF · 2022 · Q22 Relevance score: -4.43

Which one of the following materials cannot be used to make a convex lens?

CAPF · 2018 · Q11 Relevance score: -4.87

Match List-I with List-II and select the correct answer using the code given below the Lists : List-I List-H (Compound) (Type of polymer) A. Melamine 1. Linear B. Polyvinyl chloride 2. Condensation C. Terylene 3. Natural D. Cellulose 4. Cross-linked Code :

IAS · 2021 · Q94 Relevance score: -5.01

Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?