Visual Optics Practice Questions and
Answers Graded A+
A light wave passes from a vacuum into water (n=1.3333) then into high index
glass (n= 1.742), and finally into ophthalmic crown glass (n=1.523). In which of
the refractive media would frequency of the wave be the LOWEST?
A) water
B) high index glass
C) ophthalmic crown glass
D) frequency would be the same in all media - Correct answer-D
A light wave with wavelength 555 nm in a vacuum enters a refractive medium and
wavelength changes to 388.11 nm. What is the refractive index of the refractive
medium?
A) 1.333
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,B) 1.430
C) 1.523
D) Cannot be determined; insufficient information provided - Correct answer-B
Which of the following statements correctly and fully defines rectilinear
propagation of light?
(A) When incident at an angle to the normal between two refractive media,
wavefronts change direction upon entering the new medium
(B) Light rays represent plane wavefronts
(C) Light rays are parallel to the optic axis
(D) Light rays are perpendicular to advancing wavefronts - Correct answer-D
Plane wavefronts are incident normal to a spectacle lens with spherical surfaces.
After passing through the lens, the refracted waves are convergent. Why does this
happen?
(A) The lens is more curved at the center than the edges
(B) The lens is thicker at the center than the edges
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,(C) Refractive index is higher at the center of the lens than the edges
(D) Angle of incidence of light is greater at the center of the lens than the edges -
Correct answer-B
Refracted light waves are converging from a lens (Lens 1) in air. Refracted
vergence at Lens 1 is +4 D. A second lens (Lens 2) is now placed 45 cm to the right
of Lens 1. What is the required power for Lens 2 so that parallel light will emerge
after refraction through the two lens system?
(A) +2.2 D
(B) +4.0 D
(C) +4.5 D
(D) +5.0 D - Correct answer-D
Is it possible to produce a virtual image with a point source and plus lens?
(A) It is not possible
(B) A virtual image will result if the point source is placed at the primary (first
principal) focus of the lens
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, (C) A virtual image will result if the point source is placed closer to the lens than
the primary (first principal) focus.
(D) A virtual image will result if the point source is placed further from the lens
than the primary (first principal) focus. - Correct answer-C
Plane waves are incident from glass (nglass = 1.50) at an angle of 2.5 to a flat
interface between glass and air (nair = 1.00). What is the angle of refraction of the
waves as they emerge into air?
(A) 1.67
(B) 2.0
(C) 3.25
(D) 3.75 - Correct answer-D
Which schematic eye should be used to study the effect of axial length progression
(increase) on ametropia?
(A) Reduced Eye
(B) Simplified Schematic Eye
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Answers Graded A+
A light wave passes from a vacuum into water (n=1.3333) then into high index
glass (n= 1.742), and finally into ophthalmic crown glass (n=1.523). In which of
the refractive media would frequency of the wave be the LOWEST?
A) water
B) high index glass
C) ophthalmic crown glass
D) frequency would be the same in all media - Correct answer-D
A light wave with wavelength 555 nm in a vacuum enters a refractive medium and
wavelength changes to 388.11 nm. What is the refractive index of the refractive
medium?
A) 1.333
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,B) 1.430
C) 1.523
D) Cannot be determined; insufficient information provided - Correct answer-B
Which of the following statements correctly and fully defines rectilinear
propagation of light?
(A) When incident at an angle to the normal between two refractive media,
wavefronts change direction upon entering the new medium
(B) Light rays represent plane wavefronts
(C) Light rays are parallel to the optic axis
(D) Light rays are perpendicular to advancing wavefronts - Correct answer-D
Plane wavefronts are incident normal to a spectacle lens with spherical surfaces.
After passing through the lens, the refracted waves are convergent. Why does this
happen?
(A) The lens is more curved at the center than the edges
(B) The lens is thicker at the center than the edges
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,(C) Refractive index is higher at the center of the lens than the edges
(D) Angle of incidence of light is greater at the center of the lens than the edges -
Correct answer-B
Refracted light waves are converging from a lens (Lens 1) in air. Refracted
vergence at Lens 1 is +4 D. A second lens (Lens 2) is now placed 45 cm to the right
of Lens 1. What is the required power for Lens 2 so that parallel light will emerge
after refraction through the two lens system?
(A) +2.2 D
(B) +4.0 D
(C) +4.5 D
(D) +5.0 D - Correct answer-D
Is it possible to produce a virtual image with a point source and plus lens?
(A) It is not possible
(B) A virtual image will result if the point source is placed at the primary (first
principal) focus of the lens
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, (C) A virtual image will result if the point source is placed closer to the lens than
the primary (first principal) focus.
(D) A virtual image will result if the point source is placed further from the lens
than the primary (first principal) focus. - Correct answer-C
Plane waves are incident from glass (nglass = 1.50) at an angle of 2.5 to a flat
interface between glass and air (nair = 1.00). What is the angle of refraction of the
waves as they emerge into air?
(A) 1.67
(B) 2.0
(C) 3.25
(D) 3.75 - Correct answer-D
Which schematic eye should be used to study the effect of axial length progression
(increase) on ametropia?
(A) Reduced Eye
(B) Simplified Schematic Eye
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