ABO NCLE CONTACT LENS TERMS EXAM QUESTIONS AND
ANSWERS || LATEST 2025/2026 || A GRADE
Abrasion, Corneal - CORRECT ANSWER - scraped area of corneal surface,
accompanied by loss of superficial tissue (epithelium)
Acanthamoeba keratitis - CORRECT ANSWER - A rare, but serious sight-
destroying inflammation of the cornea caused by the parasite fount in contaminated
water
accommodation - CORRECT ANSWER - the ability of the crystalline lens to
adjust power to provide retinal focus of images closer than optical infinity
Add - CORRECT ANSWER - Additional amount of plus power required for
focusing at near
Albinism - CORRECT ANSWER - congenital absence or deficiency of pigment
in the iris, skin, and/or hair; usually associated with lowered visual acuity,
nystagmus, and photophobia and often accompanied by large refractive errors
ambloypia - CORRECT ANSWER - Loss of vision without any apparent disease
of the eye
ametropia - CORRECT ANSWER - A refractive error in which the eye, when in a
state of rest, does not focus the image of an object upon the retina; includes
hyperopia, myopia, and astigmatism.
,anomaly - CORRECT ANSWER - deviation from what is normal
Anterior Bevel/CN Bevel - CORRECT ANSWER - Angulation applied to the
anterior surface of a lens to reduce edge Thickness
Anterior Optical Zone (AOZ) - CORRECT ANSWER - Diameter of the anterior
power curve
aphakia - CORRECT ANSWER - Absence of the crystalline lens
Apical (apex) - CORRECT ANSWER - The extreme top or tip of a curve, e.g.
corneal apex.
Apical bearing, apical touch - CORRECT ANSWER - The posterior lens
curvature resting on the corneal apex.
aqueous humor - CORRECT ANSWER - clear, watery fluid that fills the space
between the back corneal surface and the front vitreous surface, bathing the
crystalline lens. Produced by the ciliary processes; nourishes the cornea, iris, and
lens and maintains intraocular pressure
Aqueous tears - CORRECT ANSWER - The middle layer of the tear film. The
watery component of the tears
Arbor - CORRECT ANSWER - A brass tool that holds a lens or lens blank in
place for cutting the surface or polishing
, Arcuate stain - CORRECT ANSWER - An arc shaped corneal abrasion caused by
the edge of a contact lens
Aspheric - CORRECT ANSWER - Not spherical. A posterior or anterior lens
surface design which flattens at a given rate (eccentricity) as the curve progresses
toward the periphery.
Aspheric lens - CORRECT ANSWER - a lens that resembles an ellipse, parabola,
or other conic section rather than a sphere. It can be designed to improve the fit and
comfort of a lens by paralleling the cornea more closely or to provide progressive
bifocal effect
astigmatism - CORRECT ANSWER - defective curvature of the cornea or lens of
the eye
Axial edge lift - CORRECT ANSWER - Vertical distance from the lens edge to
an extension of the base curve of a lens.
Axis, cylinder - CORRECT ANSWER - The weakest, or least curved, meridian
on the surface of a cylindrical or toric surface.
Axis, principal - CORRECT ANSWER - An imaginary line going through the
geometric center of an optical system, perpendicular to the surface.
Back toric - CORRECT ANSWER - A lens design with two principal curves at
right angles to each other on the lens posterior
ANSWERS || LATEST 2025/2026 || A GRADE
Abrasion, Corneal - CORRECT ANSWER - scraped area of corneal surface,
accompanied by loss of superficial tissue (epithelium)
Acanthamoeba keratitis - CORRECT ANSWER - A rare, but serious sight-
destroying inflammation of the cornea caused by the parasite fount in contaminated
water
accommodation - CORRECT ANSWER - the ability of the crystalline lens to
adjust power to provide retinal focus of images closer than optical infinity
Add - CORRECT ANSWER - Additional amount of plus power required for
focusing at near
Albinism - CORRECT ANSWER - congenital absence or deficiency of pigment
in the iris, skin, and/or hair; usually associated with lowered visual acuity,
nystagmus, and photophobia and often accompanied by large refractive errors
ambloypia - CORRECT ANSWER - Loss of vision without any apparent disease
of the eye
ametropia - CORRECT ANSWER - A refractive error in which the eye, when in a
state of rest, does not focus the image of an object upon the retina; includes
hyperopia, myopia, and astigmatism.
,anomaly - CORRECT ANSWER - deviation from what is normal
Anterior Bevel/CN Bevel - CORRECT ANSWER - Angulation applied to the
anterior surface of a lens to reduce edge Thickness
Anterior Optical Zone (AOZ) - CORRECT ANSWER - Diameter of the anterior
power curve
aphakia - CORRECT ANSWER - Absence of the crystalline lens
Apical (apex) - CORRECT ANSWER - The extreme top or tip of a curve, e.g.
corneal apex.
Apical bearing, apical touch - CORRECT ANSWER - The posterior lens
curvature resting on the corneal apex.
aqueous humor - CORRECT ANSWER - clear, watery fluid that fills the space
between the back corneal surface and the front vitreous surface, bathing the
crystalline lens. Produced by the ciliary processes; nourishes the cornea, iris, and
lens and maintains intraocular pressure
Aqueous tears - CORRECT ANSWER - The middle layer of the tear film. The
watery component of the tears
Arbor - CORRECT ANSWER - A brass tool that holds a lens or lens blank in
place for cutting the surface or polishing
, Arcuate stain - CORRECT ANSWER - An arc shaped corneal abrasion caused by
the edge of a contact lens
Aspheric - CORRECT ANSWER - Not spherical. A posterior or anterior lens
surface design which flattens at a given rate (eccentricity) as the curve progresses
toward the periphery.
Aspheric lens - CORRECT ANSWER - a lens that resembles an ellipse, parabola,
or other conic section rather than a sphere. It can be designed to improve the fit and
comfort of a lens by paralleling the cornea more closely or to provide progressive
bifocal effect
astigmatism - CORRECT ANSWER - defective curvature of the cornea or lens of
the eye
Axial edge lift - CORRECT ANSWER - Vertical distance from the lens edge to
an extension of the base curve of a lens.
Axis, cylinder - CORRECT ANSWER - The weakest, or least curved, meridian
on the surface of a cylindrical or toric surface.
Axis, principal - CORRECT ANSWER - An imaginary line going through the
geometric center of an optical system, perpendicular to the surface.
Back toric - CORRECT ANSWER - A lens design with two principal curves at
right angles to each other on the lens posterior
