Nao Book + Test review Book Questions with 100% Verified Correct Answers 2024/2025 The first successful contact lens were molded to the shape of the cornea known as: Corneal Hapatic Interpalpebral Gas Permeable - Correct 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 - Correct Answer Are common designs for rigid and gas perm contacts
The majority of soft lenses fit today are:
Corneal Hapatic Semi scleral Hydrophobic - Correct 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 - Correct Answer Spread evenly over the surface A contact lens with a diameter larger than that of the cornea is called a ____ lens.Corneal Hydrophilic 1 / 4
Hydrophobic Hapatic - Correct Answer Hapatic
All of the following are symptoms of a loose fitting lens except:
Constant awareness Lid sensation Burning None of the above - Correct Answer Burning Of those curves listed, which indicates the flattest base curve?
7.5 mm
37.50 D
8.6 mm 49.00 D - Correct 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 - Correct 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 - Correct 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 2 / 4
75.35 mm 30.00 D - Correct 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 - Correct Answer 2-4 D flatter than CPC
The term "hapaptic lens" is used in reference to:
Prism ballast Truncated Scleral Spin cast - Correct 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` - Correct 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 - Correct Answer All of the above
A soft CL demonstrates excessive movement. This may be remedied by:
Larger diameter lens Smaller diameter lens Flatter lens 3 / 4
Disinfected lens - Correct Answer Larger diameter lens
The term "sagittal value" refers to:
Poor fitting lens Scleral show Vaulting effect of a CL None of the above - Correct Answer Vaulting effect of a CL When determining the best lens material to use, which of hte following should be considered:
- The patient's working conditions
- Precorneal tear film
- Full time vs. part time wear
- only 2 and 3 only
- and 3 only 1, 2, and 3 - Correct Answer 1, 2, and 3
The gas permeability of a CAB lens is largely dependent upon:
Diameter of the CPC Width of the CPC Lens thickness Lens diameter - Correct Answer Lens thickness A rigid gas permeable CL with a B.C. of 7.50 mm is found to be fitting slightly tight. To improve the fit
we might consider changing the B.C. to which of the following:
7.40 mm 7.45 mm 7.55 mm 7.65 mm - Correct Answer 7.55 mm If the CPC of a rigid CL is held constant while the diameter is increased, it would result in: Tighter fit
- / 4