Fortnightly Quiz 8

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Question 1 of 20

Which of the following statement is FALSE with regard to base curve of contact lens

  • A is measured with a radiuscope
  • B determines its movement with blinking
  • C is usually measured in dioptres
  • D refers to its posterior central curvature

Question 2 of 20

Compare with spectacles, the contact lenses:

  • A decrease the amount of convergence needed in myopes
  • B increase the amount of accommodation needed in myopes
  • C cause eyestrain in presbyopic patients at an earlier age
  • D decrease the amount of accommodation needed in hypermetropes

Question 3 of 20

All of the following hypoxic induced changes are reversible EXCEPT:

  • A epithelial microcysts
  • B vascularization
  • C stromal striae
  • D endothelial guttatae

Question 4 of 20

The greatest reduction in corneal sensitivity following contact lens wear is induced by:

  • A RGP lenses
  • B low water content hydrogel lenses
  • C PMMA lenses
  • D high water content hydrogel lenses

Question 5 of 20

The chemical agent found in contact lens care systems, most likely to produce a toxic ocular response, is thought to be:

  • A chlorhexidine
  • B thiomersal
  • C polyhexanide
  • D hydrogen peroxide

Question 6 of 20

Aniridia patients can be managed by

  • A Using stock opaque lenses available from lens manufacturer
  • B Using stock tinted lenses used for enhancing light colour irides
  • C Using custom opaque lenses that can have either artificial irides or an opaque donut on the surface.
  • D both A and C

Question 7 of 20

Objective lens in telescope is always:

  • A Divergent lens.
  • B Convergent lens
  • C Meniscus lens
  • D Periscopic lens

Question 8 of 20

Low vision device system is said to be afocal or in normal adjustment when

  • A Objective and ocular lens are separated by distance equal to the absolute values of their focal length.
  • B Objective and ocular lens are conjugate
  • C Objective and ocular lens are separated by distance less than to the absolute values of their focal length
  • D Objective and ocular lens are separated by distance more than the absolute values of their focal length.

Question 9 of 20

Which of the following statement is false in context to Galilean telescope?

  • A Ocular lens is negative
  • B Length of telescope is longer
  • C Exit pupil is virtual
  • D All are incorrect

Question 10 of 20

A patient was instructed to read a magazine with magnifier, the reading material should be held

  • A farther than one focal length from the magnifier
  • B closer than one focal length from the magnifier
  • C in the front focal plane of magnifier
  • D b or c

Question 11 of 20

A patient with diagnosis of advanced glaucoma complains of glare and photophobia. What will you recommend?

  • A Photochromatic lens
  • B Yellow or amber lens
  • C polarized glass
  • D a and b

Question 12 of 20

You measure a patient with a cranial VI nerve palsy to have an 8∆ distance esotropia. How far apart do the images of a fixation light at 6 m appear to the patient?

  • A 48 cm
  • B 8 cm
  • C 24 cm
  • D 36 cm

Question 13 of 20

A 6∆ base-out and an 8∆ base-down prism are replaced by a single prism. What is the power of this prism?

  • A 10∆
  • B 14∆
  • C 7∆
  • D 2∆

Question 14 of 20

An object is located 20 cm to the left of a -2.00 D lens. Where is the image located?

  • A 20 cm to the right of the lens
  • B 50 cm to the right of the lens
  • C 33 cm to the left of the lens
  • D 14 cm to the left of the lens

Question 15 of 20

Without correction, a child complains that objects closer than 33 cm are blurry. Cycloplegic refraction measured + 6.00 D sphere OU. How much accommodation does this child have?

  • A 6.00 D
  • B 12.00 D
  • C 3.00 D
  • D 9.00 D

Question 16 of 20

A 65-year-old hyperopic patient undergoes cataract surgery in his left eye. Following surgery his refraction measures: +4.00 + 0.50 × 90 & -2.25 + 1.00 × 90 . Progressive bifocal, +2.50 add. He complains of difficulty adjusting to his new glasses. With each eye tested individually, his acuity is 20/20. Which of the following would best solve his problem?

  • A Slab-off prism
  • B Contact lenses
  • C Flat-top bifocal
  • D Cycloplegic refraction

Question 17 of 20

Which optical principle is the basis for antireflective coatings on glasses and lenses?

  • A Coherence
  • B Diffraction
  • C Interference
  • D Polarization

Question 18 of 20

By reducing the size of pinhole , effects of diffraction are minimized

  • A Plane and linearly polarized light are identical
  • B Amblyopic eye cannot detect polarized light
  • C Reflection at horizontal surfaces produces vertically polarized light
  • D a and c

Question 19 of 20

Which of the following statement regarding scattering is correct

  • A Light scattering is independent of the wavelength of incident light
  • B Large diameter collagen fibrils increase light scattering rendering the sclera opaque.
  • C Vitreous collagen fibrils are of large diameter
  • D a and b

Question 20 of 20

When prescribing spectacles

  • A Attention need only be paid to lens Centration when the lens power exceeds 4D in any one meridian.
  • B A decentration of 5 mm UP on a +1DS lens will produce a prismatic effect of 0.5∆UP
  • C A prismatic error of 0.5∆UP would be expected to produce significant symptoms in the majority of patients.
  • D Photochromics should not be prescribed to children.