ABO ABO Industry Standards 4

Question 1

Under FDA 21 CFR 801.410, dress ophthalmic lenses must pass the 'drop-ball test' using a steel ball of what diameter?

Accepted Answer

1 inch

Answer

The FDA drop-ball test requires that a 1-inch (25.4 mm) diameter steel ball dropped from 50 inches does not fracture the lens.

Question 2

What is the ANSI Z80.1 tolerance for cylinder axis in lenses with cylinder powers from 0.25D to 0.50D?

Accepted Answer

±7°

Answer

For cylinder powers between 0.25D and 0.50D, ANSI Z80.1 permits an axis tolerance of ±7°.

Question 3

In spectacle dispensing, 'pantoscopic tilt' refers to:

Accepted Answer

The vertical angle of the lens plane relative to vertical

Answer

Pantoscopic tilt is the vertical angle at which the lower edge of the lens is tilted toward the cheek relative to a vertical plane.

Question 4

Which of the following lens materials has the highest impact resistance, making it preferred for children's and safety eyewear?

Accepted Answer

Polycarbonate

Answer

Polycarbonate has the highest impact resistance of all common ophthalmic lens materials, making it the standard for safety and children's eyewear.

Question 5

When measuring the fitting height for a progressive addition lens, the measurement is taken from:

Accepted Answer

The pupil center to the lowest edge of the frame

Answer

PAL fitting height is measured from the center of the pupil vertically down to the lowest point of the lens aperture (bottom of the frame).

ABO - American Board of Optometry Practice Test