Quiz 2 Flashcards
Why shouldn’t different brands of soft contact lens solutions be mixed?
a. Lenses may tear or deteriorate faster
b. Federal Law prohibits it
c. A chemical reaction may occur causing corneal problems
d. Manufacturers will not allow it
c. A chemical reaction may occur causing corneal problems
Which of the following preservatives is a mercury based compound?
a. Thimerosal
b. Polyquad
c. Dymed
d. Sorbic Acid
a. Thimerosal
When lenses are delivered to the patient, the wearing schedule should be:
a. Determined by the patients level of comfort
b. Verbal and written
c. Unspecified
d. Determined by the refraction
b. Verbal and written
A buffering agent is added to a solution to help control:
a. PH level
b. Bacteria
c. Tonicity
d. Wettability
a. PH level
Which of the following care systems would result in the shortest life for a soft lens?
a. Heat
b. Cold chemical
c. Hydrogen Peroxide
a. Heat
Studies have shown that as high as ____% of compliant contact lens patients have contact lens cases that culture positive.
a. 75%
b. 15%
c. 42%
d. 52%
c. 42%
All of the following are functions of a soaking solution except:
a. It dissolves excess silicone molecules
b. It prevents eye infections by a contaminated lens
c. It maintains a state of hydrated equilibrium
d. It aids in cleaning the lens of ocular secretions
a. It dissolves excess silicone molecules
What is the primary function of a surfactant cleaner?
a. Remove surface scratches
b. Remove protein deposits
c. Remove loosely adherent debris from the lens surface
d. Kill microorganisms
c. Remove loosely adherent debris from the lens surface
The average PH value of human tears is:
a. 7.8
b. 7.4
c. 6.6
d. 10.0
b. 7.4
All of the following are functions of a wetting solution except:
a. It cleans the lens after removal
b. It converts the hydrophobic lens surface to a hydrophilic one
c. It provides lubrication between the lid and lens surface
d. It provides a viscous protective coating over the lens surface so the finger does not come in direct contact with the finger during insertion
a. It cleans the lens after removal
Upon delivery the wearer should be told:
a. That rigid lenses should be polished every three months
b. To remove a lens which becomes uncomfortable
c. That follow-up will not be necessary
d. That lenses will last indefinitely
b. To remove a lens which becomes uncomfortable
Which type of saline solution causes the least problems?
a. Unit dose non-preserved
b. Salt tablets
c. Sorbic acid preserved
d. Thimerosal preserved
a. Unit dose non-preserved
Which of the following disinfecting solutions would you recommend to a patient with a history of allergic reactions?
a. Thimerosal
b. Hydrogen Peroxide
c. Quatenary Ammonium
d. Chlorhexidine
b. Hydrogen Peroxide
Ingredients added to contact lens solutions to protect them from spoilage after being opened are called:
a. Preservatives
b. Buffering Agents
c. Disinfectants
d. Chelating Agents
a. Preservatives
Which of the following is most effective in removing protein buildup on soft contact lenses?
a. Sodium bicarbonate
b. Tap water
c. Enzymatic cleaner
d. Hypertonic saline
c. Enzymatic cleaner
