ABO-NCLE Practical Exam Questions With 100% Verified Answers

ABO-NCLE Practical Exam Questions With 100% Verified Answers Which statement is true regarding the properties of light? - ANSWER -Light behaves in two different ways: like a particle and like a wave. Use Prentice's Rule to find the power of a lens that is ground with 2 prism diopters 2 mm from the optical center. - ANSWER -10 diopters The visible spectrum is: - ANSWER -Between 380 and 760 nm. How does light bend when it enters a medium denser (a higher refractive index) than where it came from? - ANSWER -towards the normal The low Abbe value of polycarbonate indicates: - ANSWER -High dispersion of light. High-index lenses can help make a lens thinner by: - ANSWER -Causing the light to bend more. Single vision lens - ANSWER -lens with the same power throughout the lens Spherocylinder lens - ANSWER -lenses with a sphere (to correct nearsightedness or farsightnedness) and a cylinder (to correct astigmatism) multifocal lenses - ANSWER -lenses in which the lowwr portion of the lens has an add that makes it more magnified in power than the rest of the lens. A bifocal has two powers and a trifocal has three chromatic aberration - ANSWER -when the lens does not focus all the wavelengths of color to one point distortion - ANSWER -when the different points in the periphery of a lens have different amounts of magnification spherical aberration - ANSWER -occurs when parallel light rays move along the optical axis coma - ANSWER -the typr of lens aberration called coma occurs when parallel light rays going through a lens focus in a ring shaped pattern with a V shaped or comet like flare on one end of the image abbe value - ANSWER -the amount of chromatic abberation produced by a lens material abbe value for plastic - ANSWER -1.74= 32 abbe 1.7= 36 abbe 1.67= 32 1.6= 42 abbe abbe value for polycarbonate - ANSWER -30 abbe value for trivex - ANSWER -45 abbe value for glass - ANSWER -58 abbe value for standard plastic - ANSWER -58 curvature of field - ANSWER -occurs when the things a person sees through the edge of a lens dont focus on the retina at the same time as the objects the person sees through the center of the lens Oblique or marginal astigmatism - ANSWER -Occurs when rays of light pass through a lens at a slant aspheric lens - ANSWER -Minimizes spherical aberrations vogels formula - ANSWER -The optimal base curve for a lens lenticular lenses - ANSWER -Have lesser or no power in the carrier portion of the lens diopter - ANSWER -Unit of power of a lens. focal length - ANSWER -the inverse of the power of a lens in meters vertex - ANSWER -the distance from the lens to persons eye A lens that is convex on one side and flat on the other - ANSWER -plano-convex an abbe value is a measure of - ANSWER -chromatic aberration a meniscus lens that thinner in the center than in the periphery - ANSWER -minus meniscus lens the curvature of the surface of a plus lens is - ANSWER -convex light will always bend toward the ----- of a prism - ANSWER -base what do aspheric lens do? - ANSWER -they minimize spherical aberrations plus and minus lens are thicker and thinner where? - ANSWER -a plus lens will be thicker in the center and have thinner edges - a minus lens will be thinner in the middle with thicker edges Simple myopic astigmatism - ANSWER -the eye is normal in one meridian and 90 degress away the eye is nearsighted Simple hyperopic astigmatism - ANSWER -The eye is normal in one meridian and 90 degrees away it is farsighted Compound myopic astigmatism - ANSWER -The eye is nearsighted in both meridians, but more nearsighted in one meridian than the other. Mixed astigmatism - ANSWER -one meridian is nearsighted and the other is farsighted