OPT-1156 Ophthalmic Lens II Unit 4 Flashcards
As light strikes a lens with a spherical front surface, it refracts more at the periphery than near the center
True
Most ophthalmic lenses have no aberrations.
False
In curvature of field, the image is curved convex toward the object
False
All lenses moved farther from the eye will gain in plus power. We compensate for this by adding minus power.
True
When light strikes an object, 3 things occur.
Refraction
Absorption
Reflection
Vertex Distance Compensation should be considered when the total power of the lens, in any meridian, is +/- 7.00 or greater.
True
In the surface power formula, we must be sure that “r” (radius) is in Meters, not millimeters or centimeters.
True
In coma, the aberration is a result of rays of light parallel to the lens surface.
False
A high minus lens will show ____________ distortion
Barrel
A surface with a shorter radius will have a flatter curve
False
As a ray of light passes from a more dense to a less dense material at an oblique angle, the refracted ray will be deviated _________ the normal.
parallel to
As a ray of light passes from a less dense to a more dense material at an oblique angle, the refracted ray will be deviated _________ the normal.
toward
A concave surface has ________ dioptric power.
Minus
The law of Reflection states that, “The angle of incidence is always greater than the angle of reflection”.
False
A plano surface has __________ dioptric power.
Zero
