Quiz For Contact Lenses for the Correction of Astigmatism

________________astigmatism cannot be corrected by spectacle lenses.

In ______________________astigmatism the cornea is steeper in the vertical meridian and flatter in the horizontal

In ______________________astigmatism the cornea is steeper in the horizontal meridian and flatter in the vertical.

In simple myopic astigmatism:

In simple hyperopic astigmatism:

In compound myopic astigmatism:

In compound hyperopic astigmatism:

In mixed astigmatism:

When are bitoric lenses prescribed?

For which of the following could prism ballast lenses be used:

Rx: -3.50 +1.25 x 90
K: 42.00 x 180/43.75 x 90
A rigid contact lens fit “on K” would require which of the following powers?

The power of the tear lens in the previous questions is:

Rx: -2.25 -0.25 x 180
What is the power of a rigid contact lens fit 0.75 diopters steeper than K?

The power and thickness of the lacrimal lens will vary with the:

The rotation of a toric contact lens may be inhibited by:

When a lens is ___________a portion of it is sectioned off.

The expression LARS stands for:

Astigmatic contact lenses may be classified into the following categories:

_______________________maintain their shape on the eye and don’t conform to the unequal contours of an astigmatic cornea

The tear lens behind the RGP contact lens :

Residual astigmatism may be caused by:

Anterior toric contact lenses with spherical back surfaces:

Posterior base curve toric lenses

When a rigid lens is fit on K the tear lens:

When a rigid lens is fit steeper than K the tear lens:

When a rigid lens is fit flatter than K the tear lens:

Astigmatism is:

______________is used for the correction of astigmatism

______________________astigmatism can be caused by a diseased or damaged cornea

Axis is always recorded as angle in degrees between ______and __________degrees.