ABO ABO Industry Standards 3

Question 1

In ophthalmic lens standards, what is the 'optical center' of a single vision lens?

Accepted Answer

The point on the lens where prismatic effect is zero

Answer

The optical center is the point on a lens through which light passes without being deviated (zero prismatic effect).

Question 2

What is the standard pupillary distance measurement method used when fitting progressive addition lenses?

Accepted Answer

Monocular PD measured from each pupil to the bridge

Answer

For PALs, monocular PD is the preferred method, measuring from the center of each pupil to the bridge of the nose independently.

Question 3

According to FDA regulations, which lens material is exempt from the standard dress impact (drop-ball) test requirement?

Accepted Answer

Glass lenses over 3mm thick

Answer

FDA regulations exempt glass lenses that are at least 3mm thick at their thinnest point from the drop-ball impact test.

Question 4

What does the 'Abbe value' of a lens material indicate?

Accepted Answer

The degree of chromatic aberration (color dispersion)

Answer

The Abbe value (V-number) measures chromatic aberration; a higher value means less color fringing and better optical clarity.

Question 5

Which organization publishes the ANSI Z80 series of ophthalmic standards in the United States?

Accepted Answer

The American National Standards Institute

Answer

ANSI (American National Standards Institute) publishes and maintains the Z80 series, which includes standards for ophthalmic lenses, frames, and instruments.

ABO - American Board of Optometry Practice Test

ABO - American Board of Optometry Practice Test

ABO ABO Industry Standards 3