Lensmeter Hints Handout Practice Flashcard

Front

Compound ophthalmic lenses usually consist of

Back

both cylindrical and spherical surfaces

Front

When neutralizing a pair of prescription lenses, the lensometer table should be set to allow the reading of:

Back

The optical center of the strongest lens

Front

When using a lensmeter, which of the following should be adjusted first? The power drum, The eyepiece, The lens stop, The reticle

Back

The eyepiece

Front

The target in a lensmeter clears at +0.25 without a lens in the instrument. Which of the following may need adjusting? The eyepiece and the power drum, The lens stop and the power drum, The reticle and the eyepiece, The stop and the reticle

Back

The eyepiece and the power drum

Front

A lens is being neutralized and the axis wheel is at 115. The sphere lines come to focus at +1.25 and the cylinder lines come into focus at -1.75. What is the correct prescription?

Back

+1.25 -3.00 x115

Front

While neutralizing a spherocylinder lens, you obtain the following readings at axis 045:
Sphere lines clear at -0.50
Cylinder lines clear at +1.25. Which of the following prescriptions is correct?
- -0.50 -1.25 x045
- -0.50 +1.75 x045
- +1.25 -1.75 x045
- +1.25 +1.25 x045

Back

-0.50 +1.75 x045

Front

What is the dioptric power difference between the lenses in this Rx? OD: -0.75, OS: +0.25

Back

1.00 D

Front

The power of a cylinder along its specified axis contains:

Back

No cylinder power

Front

Which of the following conditions is this lens designed to correct? Rx: +0.50 - 0.75 x010
Options: Compound Hyperopic Astigmatism, Compound Myopic Astigmatism, Mixed Astigmatism, Antimetropia

Back

Mixed Astigmatism

Front

A concave lens:

Back

is thinner in the center than at the edges