Nao Book + Test review Book
The first successful contact lens were molded to the shape of the cornea known as:
Corneal
Hapatic
Interpalpebral
Gas Permeable - Answer-Hapatic
Corneal Contact lenses:
Are a typical soft contact lens design
Bridge the limbus and some of the sclera
Are last resort contact lenses
Are common designs for rigid and gas perm contacts - Answer-Are common designs for rigid and gas
perm contacts
The majority of soft lenses fit today are:
Corneal
Hapatic
Semi scleral
Hydrophobic - Answer-Semi scleral
,A liquid coming in contact with a hydrophilic lens material with a relatively small wetting angle would be
likely to:
Form beads on the surface
Quickly evaporate
Spread evenly over the surface
None of the above - Answer-Spread evenly over the surface
A contact lens with a diameter larger than that of the cornea is called a ____ lens.
Corneal
Hydrophilic
Hydrophobic
Hapatic - Answer-Hapatic
All of the following are symptoms of a loose fitting lens except:
Constant awareness
Lid sensation
Burning
None of the above - Answer-Burning
Of those curves listed, which indicates the flattest base curve?
7.5 mm
37.50 D
8.6 mm
49.00 D - Answer-37.50 D
,A contact lens was ordered with a base curve of 7.85 mm but was received back from the lab with a
base curve of 7.80 mm. The base cure of the actual lens is:
0.25 D flatter
0.25 D steeper
0.50 D flatter
0.50 D steeper - Answer-0.25 D steeper
It is noticed that a rigid CL containing a base curve of 7.42mm is fitting quite loose. A tighter fit may be
achieved by changing the B.C. to:
7.46 mm
7.85 mm
8.04 mm
None of the above - Answer-None of the above
A CL has a B.C. of 7.50 mm. Its posterior peripheral curve would most likely be:
7.45 mm
42.50 D
75.35 mm
30.00 D - Answer-42.50 D
The secondary curve of a rigid contact lens generally:
Is steeper than the CPC (Central posterior curve)
1-2 D flatter than CPC
2-4 D flatter than CPC
None of the above - Answer-2-4 D flatter than CPC
, The term "hapaptic lens" is used in reference to:
Prism ballast
Truncated
Scleral
Spin cast - Answer-Scleral lens
The CPC of a CL measures 7.5 mm radius of curvature. Its power in diopters is:
41.00 D
42.00 D
45.00 D
47.00 D` - Answer-45.00 D
The fitting characteristics of a gas permeable rigid CL may be altered by:
Changing the CPC's radius of curvature
Increasing the diameter
Widening the posterior peripheral curve
All of the above - Answer-All of the above
A soft CL demonstrates excessive movement. This may be remedied by:
Larger diameter lens
Smaller diameter lens
Flatter lens
Disinfected lens - Answer-Larger diameter lens
The term "sagittal value" refers to:
The first successful contact lens were molded to the shape of the cornea known as:
Corneal
Hapatic
Interpalpebral
Gas Permeable - Answer-Hapatic
Corneal Contact lenses:
Are a typical soft contact lens design
Bridge the limbus and some of the sclera
Are last resort contact lenses
Are common designs for rigid and gas perm contacts - Answer-Are common designs for rigid and gas
perm contacts
The majority of soft lenses fit today are:
Corneal
Hapatic
Semi scleral
Hydrophobic - Answer-Semi scleral
,A liquid coming in contact with a hydrophilic lens material with a relatively small wetting angle would be
likely to:
Form beads on the surface
Quickly evaporate
Spread evenly over the surface
None of the above - Answer-Spread evenly over the surface
A contact lens with a diameter larger than that of the cornea is called a ____ lens.
Corneal
Hydrophilic
Hydrophobic
Hapatic - Answer-Hapatic
All of the following are symptoms of a loose fitting lens except:
Constant awareness
Lid sensation
Burning
None of the above - Answer-Burning
Of those curves listed, which indicates the flattest base curve?
7.5 mm
37.50 D
8.6 mm
49.00 D - Answer-37.50 D
,A contact lens was ordered with a base curve of 7.85 mm but was received back from the lab with a
base curve of 7.80 mm. The base cure of the actual lens is:
0.25 D flatter
0.25 D steeper
0.50 D flatter
0.50 D steeper - Answer-0.25 D steeper
It is noticed that a rigid CL containing a base curve of 7.42mm is fitting quite loose. A tighter fit may be
achieved by changing the B.C. to:
7.46 mm
7.85 mm
8.04 mm
None of the above - Answer-None of the above
A CL has a B.C. of 7.50 mm. Its posterior peripheral curve would most likely be:
7.45 mm
42.50 D
75.35 mm
30.00 D - Answer-42.50 D
The secondary curve of a rigid contact lens generally:
Is steeper than the CPC (Central posterior curve)
1-2 D flatter than CPC
2-4 D flatter than CPC
None of the above - Answer-2-4 D flatter than CPC
, The term "hapaptic lens" is used in reference to:
Prism ballast
Truncated
Scleral
Spin cast - Answer-Scleral lens
The CPC of a CL measures 7.5 mm radius of curvature. Its power in diopters is:
41.00 D
42.00 D
45.00 D
47.00 D` - Answer-45.00 D
The fitting characteristics of a gas permeable rigid CL may be altered by:
Changing the CPC's radius of curvature
Increasing the diameter
Widening the posterior peripheral curve
All of the above - Answer-All of the above
A soft CL demonstrates excessive movement. This may be remedied by:
Larger diameter lens
Smaller diameter lens
Flatter lens
Disinfected lens - Answer-Larger diameter lens
The term "sagittal value" refers to:
