OPTICIANS UPDATED 2026 EXAM SCRIPT QUESTIONS AND
SOLUTIONS RATED A+
✔✔Pantoscopic angle - ✔✔(1) In standard alignment, that angle by which the frame
front deviates from the vertical (lover rims farther inward than upper rims) when the
spectacles are held with the temples horizontal. (2) In fitting, the angle that the frame
front makes with the frontal plane of the wearer's face when the lower rims are closer to
the face than the upper rims.
Antonym: retroscopic angle; synonym: pantoscopic tilt.
✔✔Retroscopic angle - ✔✔The angle that the frame front makes with the frontal plane
of the wearer's face when the lower rims are farther from the face than the upper rims.
Antonym: pantosopic angle; synonym: retroscopic tilt.
✔✔Splay angle - ✔✔(1) The angle formed by the side of the nose with a straight
anterior-posterior surface that would bisect it vertically (also called transverse angle)/ (2)
The angle the face of a nosepad makes with a plane perpendicular to that of the frame
front when viewed from above.
✔✔Temple fold angle - ✔✔The angle formed when a temple is folded to a closed
position.
✔✔Vertical angle - ✔✔When viewed from the side, that angle formed between the
plane of the lenses and the long axis of the adjustable nosepads.
✔✔Angle of deviation - ✔✔The difference between the angle of incidence and the angle
of refraction.
✔✔Anisometropia - ✔✔A condition in which one eye differs significantly in refractive
power form the other.
✔✔ANSI - ✔✔American National Standards Institute
✔✔Aperture - ✔✔(1) An opening or hole that admits only a portion of light from a given
source or sources. (2) The central, optically correct portion of a lenticular lens.
✔✔Lens aperture - ✔✔The portion of the spectacle frame that accepts the lens.
Synonym: lens opening.
✔✔Apex - ✔✔The junction point at which the two nonparallel surfaces of a prism meet.
✔✔Aphakic - ✔✔A person or eye whose crystalline lens has been removed.
✔✔AR - ✔✔Antireflection coating
,✔✔Arm - ✔✔In a semirimless mounting, the metal reinforcement that follows the upper
posterior surface of a spectacle lens and joins the centerpiece to the endpiece.
Synonyms: bar, browbar.
✔✔Guard arm - ✔✔A synonym for pad arm.
✔✔Pad arm - ✔✔A metal piece that connects an adjustable nosepad to the front of a
frame.
✔✔Aspheric - ✔✔A nonspherical surface. An aspheric lens surface generally decreases
in power peripherally to correct for aberrations found in the periphery of a lens.
✔✔Full-field aspheric - ✔✔An aspheric lens that begins its asphericity where the small
central spheric region leaves off. It continues in its asphericity to the edge of the lens
blank.
✔✔Astigmatism - ✔✔The condition in which light focuses as two line images at different
distances along the optic axis instead of at one single point. These two-line foci are at
right angles to one another.
✔✔Oblique astigmatism - ✔✔The lens aberration that occurs when rays from an off-axis
point pass through the lens and light focuses as two line images instead of a single
point.
Synonyms: radial astigmatism, marginal astigmatism.
✔✔ASTM - ✔✔American Society for Testing and Materials.
✔✔Axis of a cylinder - ✔✔An imaginary reference line used to specify cylinder or
spherocylinder lens orientation and corresponding to the meridian of least refractive
power.
✔✔Optical axis - ✔✔The line that passes through the center of a lens on which the radii
of curvature of the front and back surfaces fall.
✔✔Back base curve - ✔✔The weaker back-surface curve of a minus cylinder-form lens.
When the lens is a minus cylinder-form lens, the back base curve and the toric base
curve are the same.
✔✔Base - ✔✔In a prism, the edge of maximum surface separation opposite the apex.
✔✔Base curve - ✔✔The surface curve of a lens that becomes the basis from which the
other remaining curves are calculated.
, ✔✔Base Down - ✔✔Vertical placement of prism such that the base is at 270 degrees
on a degree scale.
✔✔Base In - ✔✔Horizontal placement of prism such that the base is toward the nose.
✔✔Base Out - ✔✔Horizontal placement of prism such that the base is toward the side
of the head.
✔✔Base Up - ✔✔Vertical placement of prism such that the base is at 90 degrees on a
degree scale
✔✔BCD - ✔✔Boxing center distance.
See Distance, boxing center.
✔✔Bevel - ✔✔The angled edge of the spectacle lens.
✔✔Pin bevel - ✔✔Synonym for safety bevel.
✔✔Safety bevel - ✔✔(1) To remove the sharp interface between lens surface and bevel
surface and the sharp point at the bevel apex. (2) The smoothed interface between lens
surface and bevel surface and the smoothed lens bevel apex.
✔✔V-bevel - ✔✔A lens edge configuration having the form of a V across the whole
breadth of the lens edge.
✔✔Blended bifocal lens - ✔✔A bifocal lens constructed from one piece of lens material
and having the demarcation line around the bifocal segment smoothed out so as not to
be visible to an observer. Usually round segment lenses that have the demarcation line
between the distant portion and the bifocal portion smoothed away.
✔✔Curved top bifocal - ✔✔A bifocal lens having a segment that is round in the lower
portion and gently curve don the top of the segment.
✔✔Executive bifocal - ✔✔American Optical's trade name for the Franklin-style bifocal.
The line runs the length horizontally across the lens.
✔✔Flat-top bifocal - ✔✔A bifocal with a segment that is round in the lower half but flat
on the top.
✔✔Minus add bifocal - ✔✔A bifocal with a large round segment at the top of the lens.
The segment is powered for distance viewing and the rest for the lens for near viewing.
Synonyms: Rede-Rite bifocal, upcurve bifocal.
SOLUTIONS RATED A+
✔✔Pantoscopic angle - ✔✔(1) In standard alignment, that angle by which the frame
front deviates from the vertical (lover rims farther inward than upper rims) when the
spectacles are held with the temples horizontal. (2) In fitting, the angle that the frame
front makes with the frontal plane of the wearer's face when the lower rims are closer to
the face than the upper rims.
Antonym: retroscopic angle; synonym: pantoscopic tilt.
✔✔Retroscopic angle - ✔✔The angle that the frame front makes with the frontal plane
of the wearer's face when the lower rims are farther from the face than the upper rims.
Antonym: pantosopic angle; synonym: retroscopic tilt.
✔✔Splay angle - ✔✔(1) The angle formed by the side of the nose with a straight
anterior-posterior surface that would bisect it vertically (also called transverse angle)/ (2)
The angle the face of a nosepad makes with a plane perpendicular to that of the frame
front when viewed from above.
✔✔Temple fold angle - ✔✔The angle formed when a temple is folded to a closed
position.
✔✔Vertical angle - ✔✔When viewed from the side, that angle formed between the
plane of the lenses and the long axis of the adjustable nosepads.
✔✔Angle of deviation - ✔✔The difference between the angle of incidence and the angle
of refraction.
✔✔Anisometropia - ✔✔A condition in which one eye differs significantly in refractive
power form the other.
✔✔ANSI - ✔✔American National Standards Institute
✔✔Aperture - ✔✔(1) An opening or hole that admits only a portion of light from a given
source or sources. (2) The central, optically correct portion of a lenticular lens.
✔✔Lens aperture - ✔✔The portion of the spectacle frame that accepts the lens.
Synonym: lens opening.
✔✔Apex - ✔✔The junction point at which the two nonparallel surfaces of a prism meet.
✔✔Aphakic - ✔✔A person or eye whose crystalline lens has been removed.
✔✔AR - ✔✔Antireflection coating
,✔✔Arm - ✔✔In a semirimless mounting, the metal reinforcement that follows the upper
posterior surface of a spectacle lens and joins the centerpiece to the endpiece.
Synonyms: bar, browbar.
✔✔Guard arm - ✔✔A synonym for pad arm.
✔✔Pad arm - ✔✔A metal piece that connects an adjustable nosepad to the front of a
frame.
✔✔Aspheric - ✔✔A nonspherical surface. An aspheric lens surface generally decreases
in power peripherally to correct for aberrations found in the periphery of a lens.
✔✔Full-field aspheric - ✔✔An aspheric lens that begins its asphericity where the small
central spheric region leaves off. It continues in its asphericity to the edge of the lens
blank.
✔✔Astigmatism - ✔✔The condition in which light focuses as two line images at different
distances along the optic axis instead of at one single point. These two-line foci are at
right angles to one another.
✔✔Oblique astigmatism - ✔✔The lens aberration that occurs when rays from an off-axis
point pass through the lens and light focuses as two line images instead of a single
point.
Synonyms: radial astigmatism, marginal astigmatism.
✔✔ASTM - ✔✔American Society for Testing and Materials.
✔✔Axis of a cylinder - ✔✔An imaginary reference line used to specify cylinder or
spherocylinder lens orientation and corresponding to the meridian of least refractive
power.
✔✔Optical axis - ✔✔The line that passes through the center of a lens on which the radii
of curvature of the front and back surfaces fall.
✔✔Back base curve - ✔✔The weaker back-surface curve of a minus cylinder-form lens.
When the lens is a minus cylinder-form lens, the back base curve and the toric base
curve are the same.
✔✔Base - ✔✔In a prism, the edge of maximum surface separation opposite the apex.
✔✔Base curve - ✔✔The surface curve of a lens that becomes the basis from which the
other remaining curves are calculated.
, ✔✔Base Down - ✔✔Vertical placement of prism such that the base is at 270 degrees
on a degree scale.
✔✔Base In - ✔✔Horizontal placement of prism such that the base is toward the nose.
✔✔Base Out - ✔✔Horizontal placement of prism such that the base is toward the side
of the head.
✔✔Base Up - ✔✔Vertical placement of prism such that the base is at 90 degrees on a
degree scale
✔✔BCD - ✔✔Boxing center distance.
See Distance, boxing center.
✔✔Bevel - ✔✔The angled edge of the spectacle lens.
✔✔Pin bevel - ✔✔Synonym for safety bevel.
✔✔Safety bevel - ✔✔(1) To remove the sharp interface between lens surface and bevel
surface and the sharp point at the bevel apex. (2) The smoothed interface between lens
surface and bevel surface and the smoothed lens bevel apex.
✔✔V-bevel - ✔✔A lens edge configuration having the form of a V across the whole
breadth of the lens edge.
✔✔Blended bifocal lens - ✔✔A bifocal lens constructed from one piece of lens material
and having the demarcation line around the bifocal segment smoothed out so as not to
be visible to an observer. Usually round segment lenses that have the demarcation line
between the distant portion and the bifocal portion smoothed away.
✔✔Curved top bifocal - ✔✔A bifocal lens having a segment that is round in the lower
portion and gently curve don the top of the segment.
✔✔Executive bifocal - ✔✔American Optical's trade name for the Franklin-style bifocal.
The line runs the length horizontally across the lens.
✔✔Flat-top bifocal - ✔✔A bifocal with a segment that is round in the lower half but flat
on the top.
✔✔Minus add bifocal - ✔✔A bifocal with a large round segment at the top of the lens.
The segment is powered for distance viewing and the rest for the lens for near viewing.
Synonyms: Rede-Rite bifocal, upcurve bifocal.
