Frame material identification

1 Which of the following should have a marking on the frame to indicate the frame material? (A) Aluminium; (B) Cellulose nitrate; (C) Carbon fibre (D) PMMA; (E) Co-polyamide.
The correct answer is E. More recent co-polyamide frames do not use 'in line' glazing making identification difficult. They should be marked as SPX.

2 Which of the following should not be supplied as a spectacle frame material on safety grounds? (A) Aluminium; (B) Cellulose nitrate; (C) Carbon fibre; (D) PMMA; (E) Co-polyamide.
The correct answer is B. Cellulose nitrate is now banned in some countries as a frame material as its low combustion point presents a safety hazard.

3 Slab or routed frames made of plastics can be identified by: (A) Swept round lugs and integral pads; (B) Two tone colours, and reinforced sides;(C) Laminated material and a bumped bridge; (D) Reinforcement at the lug only; (E) An identifying manufacturer's marking.
The correct answer is C. Slab frames are often laminated and the bridge is 'bumped.

4 Which of the following is true? (A) Optyl and SPX can be differentiated by their sides; (B) Optyl and SPX can be differentiated as only one has swept round lugs; (C) Optyl and SPX can be differentiated by the way the front has been made; (D) Optyl and SPX cannot be differentiated by the sides; (E) Optyl and SPX are the same material.
The correct answer is A. Optyl frames require reinforced sides which have been adapted at the butt only.

5 The properties of cellulose acetate include that it: (A) Smells of camphor and is highly flammable; (B) Has a low softening point and can be injection moulded; (C) Burns rapidly and can be adjusted at about 80