NCLE SAM'S Test Flashcards
The first successful contact lenses which were originally molded to conform to the shape of the
cornea were known as lenses.
haptic
Corneal contact lenses:
are the most conmon design for rigid and gas permable lenses
The majority of soft lenses fit today are:
semi-scleral
A liquid coming in contact with a hydrophilic lens material with a relatively small wetting angle
would be likely to:
spread evenly over its surface
A contact lens with a diameter larger than that of the cornea is
haptic
All of the following are symptoms of a loose fitting lens except:
burning
A contact lens was ordered with a base curve of 7.85 mm but was received back from the laboratory
with a base curve measuring 7.80 mm. The base curve ofthe actual lens is:
0.25 D steeper than the lens ordered
A contact lens has a base curve of7.50 mm. Its posterior peripheral curve would most likely be
Your answer:
42.50 D
The secondary curve of a rigid contact lens generally:
2 to 4 diopters flatter than the CPC
The term “Haptic Lens” is used in reference to:
a scleral lens
The CPC of a contact lens measures 7.5 mm radius of curvature. Its power in diopters is:
45.00
A soft contact lens demonstrates excessive movement. This may be remedied by:
a larger diameter lens
The term “sagittal value” refers to:
the vaulting effect of a contact lens
When determining the best lens material to use, which of the following should be considered?
the patient’s working conditions
- precomeal tear film
- full time vs. part time wear
The gas permeability of a CAB lens is largely dependent upon:
the lens thickness
A rigid gas permeable lens with a base curve of 7.50 mm is found to be fitting slightly tight. To
improve the fit we might consider changing the base curve to which of the following?
7.55
If the CPC of a rigid contact lens is held constant while the diameter is increased, it would result in;
a tighter fit
When compared with PMMA which of the following is not true about CAB lenses?
they have excellent shape retention
HEMA is an abbreviation commonly used to describe:
soft lenses
The chief reason to utilize a ballasted contact lens is:
to inhibit lens rotation
