ABO/NAO 5
what is polyamide - ✔️✔️a nylon-based material that is very strong. it can be made
thinner and is lighter than cellulose acetate. can be made translucent, is resistant to
chemicals and solvents and is hypoallergenic
a plus lens moved downward from the primary position results in what prism effect -
✔️✔️base down / when looking above the center of a plus lens a base down effect is
induced
when fitting a patient with progressive addition lenses for optimum performance, what is
the vertex and pantoscopic tilt, and is face form required? - ✔️✔️the frame should have
sufficient face form, a short vertex distance as long as the eyelashes do not touch the
lens and should be adjustable for pantoscopic angle of 10 to 12 degrees
what is the average convergence distance in children - ✔️✔️2mm instead of 3mm in
adults
what is the refractive index of highlite lenses - ✔️✔️1.70
chem-tempering makes a clear glass lens more impact resistant by placing the lens in a
potassium nitrate bath. the lens undergoes a process known as what? - ✔️✔️ion
exchange
what is the formula for the index of refraction - ✔️✔️index of refraction=velocity of light
in air over velocity of light in other media
which part distributes the weight of the frame over the nose pad area and the crest of
the nose - ✔️✔️strap bridge
the angle of incidence, for which the angle of refraction is 90 degrees is called the : -
✔️✔️critical angle
what is the most commonly used prescription for correcting esotropia caused by muscle
imbalance - ✔️✔️base out prism/ one eye turns inward(sometimes both) a prism
displaces an image towards its apex
what happens to vertex distance for evey1 diopter increase in base curve? -
✔️✔️increases approximately 0.6mm
how much does the 5/8 inch steel ball weigh for preforming a drop ball test for dress
safety lenses - ✔️✔️6/10 ounce
what is polyamide - ✔️✔️a nylon-based material that is very strong. it can be made
thinner and is lighter than cellulose acetate. can be made translucent, is resistant to
chemicals and solvents and is hypoallergenic
a plus lens moved downward from the primary position results in what prism effect -
✔️✔️base down / when looking above the center of a plus lens a base down effect is
induced
when fitting a patient with progressive addition lenses for optimum performance, what is
the vertex and pantoscopic tilt, and is face form required? - ✔️✔️the frame should have
sufficient face form, a short vertex distance as long as the eyelashes do not touch the
lens and should be adjustable for pantoscopic angle of 10 to 12 degrees
what is the average convergence distance in children - ✔️✔️2mm instead of 3mm in
adults
what is the refractive index of highlite lenses - ✔️✔️1.70
chem-tempering makes a clear glass lens more impact resistant by placing the lens in a
potassium nitrate bath. the lens undergoes a process known as what? - ✔️✔️ion
exchange
what is the formula for the index of refraction - ✔️✔️index of refraction=velocity of light
in air over velocity of light in other media
which part distributes the weight of the frame over the nose pad area and the crest of
the nose - ✔️✔️strap bridge
the angle of incidence, for which the angle of refraction is 90 degrees is called the : -
✔️✔️critical angle
what is the most commonly used prescription for correcting esotropia caused by muscle
imbalance - ✔️✔️base out prism/ one eye turns inward(sometimes both) a prism
displaces an image towards its apex
what happens to vertex distance for evey1 diopter increase in base curve? -
✔️✔️increases approximately 0.6mm
how much does the 5/8 inch steel ball weigh for preforming a drop ball test for dress
safety lenses - ✔️✔️6/10 ounce
