ABO/NAO 5 QUESTIONS WITH ACTUAL SOLUTIONS

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 ouncecataract spectacle lenses are best if they are made with what? - ️️aspheric curves/lenses what is the name of the ray that can pass through a lens without being refracted - ️️the axial ray the velocity of light is the least in - ️️flint glass