ABO NOCE Basic Opticianry Spectacle Lens Aberrations 2

Question 1

Which aberration causes straight lines to appear curved when viewed through the periphery of a lens?

Accepted Answer

Distortion

Answer

Spherical aberration

Answer

Coma

Answer

Oblique astigmatism

Question 2

Pincushion distortion is most commonly associated with which type of lens?

Accepted Answer

High plus lenses

Answer

High minus lenses

Answer

Piano lenses

Answer

Photochromic lenses

Question 3

What is the primary optical aberration corrected by aspheric lens designs?

Accepted Answer

Spherical aberration

Answer

Chromatic aberration

Answer

Distortion

Answer

Coma

Question 4

Oblique astigmatism occurs when light rays pass through a lens at an angle. At what lens zone is this aberration most problematic?

Accepted Answer

Peripheral zone

Answer

Optical center

Answer

Near zone

Answer

Progressive corridor

Question 5

Which Seidel aberration creates a comet-shaped blur and is caused by off-axis light passing through different lens zones?

Accepted Answer

Coma

Answer

Distortion

Answer

Field curvature

Answer

Chromatic aberration

Question 6

Field curvature aberration means the image formed by a lens lies on a curved surface rather than a flat plane. How does this affect the wearer?

Accepted Answer

Peripheral objects cannot be brought to sharp focus simultaneously with central objects

Answer

Central vision is blurred while peripheral is clear

Answer

The entire visual field appears equally sharp

Answer

Colors appear separated at the edges of vision

Question 7

Which lens design feature helps minimize the combined effect of oblique astigmatism and field curvature in spectacle lenses?

Accepted Answer

Best-form (corrected curve) design

Answer

Tinted coating

Answer

Anti-reflective coating

Answer

Polycarbonate material