Optometry and ophthalmology mcq part: 06

01. In the absence of lens accommodation, a myopic eye focuses images:

1. a. in front of the lens
2. b. In front of the retina✓
3. c. behind the retina
4. d. Behind the cornea

02. Which of the following is a risk factor for retinal detachment?

1. a. black race
2. b. male sex
3. c. Hypermetropia
4. d. myopia✓

03. At 6m distance from the patient, the 6/6 letters shall subtend an angle of ________ in the eye .

1. a. 1 minutes of arc
2. b. 1 degree
3. c. 5 minutes of arc✓
4. d. 5 degrees

04. A person standing in front of mirror finds his image larger than himself. This implies that the mirror is :

1. a) Convex
2. b) Concave✓
3. c) Plane
4. d) Parabolic

05. Retinoscopy on a -2.00D myope at 2/3 meters, neutralization occurs with power

1. a.-0.5D✓
2. b. -1.0D
3. c. 0.0D
4. d. +0.5D

06. The refractive error associated with senile Nuclear cataract

1. a. Hypermetropia
2. b. Myopia ✓
3. c. Astigmatism
4. d. Presbyopia

07. Snellens chart is based on what type of visual acuity?

1. A. Min. visible
2. B. Min. resolution✓
3. C.Vernier acuity
4. D. All of the above

08. A X8 loupe has an equivalent power of _______ dioptres.

1. A) 2
2. B) 8
3. C) 16
4. D) 32✓

Magnification of a lens is 1/4th of power, 4D lens has magnification of 1X. Similarly power of 8X lens will be 8*4=32D

09. A decentration of 10 mm from the optical centre of a +5 dioptre lens produces a prismatic effect of _______ prism dioptres.

1. A) 0.5
2. B) 5✓
3. C) 10
4. D) 50

Prentice’s Rule Δ = cD This equation can be used to calculate the prism induced by decentration. Prentice’s rule states that prism in diopters (Δ) is equal to the decentration distance (c) in centimeters multiplied by the lens power (D).

10. The image produced by a negative lens will not be ______ .

1. A) real✓
2. B) diminished in size
3. C) erect
4. D) virtual

The image produced by convex mirror and concave lens are always virtual

11. One prism dioptre (∆) produces displacement of an object by _______.

1. A) 1mm
2. B) 1cm✓
3. C) 10cm
4. D) 1m

12. The image formed by a plane mirror is always

1. A. Real and erect
2. B. Virtual and erect✓
3. C. Real and inverted
4. D. Virtual and inverted

13. A convex lens acts as a magnifying lens if the object is placed ..........

1. A. Between Focus(F) and optical centre of lens✓
2. B. Between focus(F) and centre of curvature (2F)
3. C. Beyond centre of curvature ( 2F)
4. D. Anywhere

14. SI unit of power of a lens is

1. A. Diopter✓
2. B. Snellen
3. C. Meter
4. D. cm

15. 1 D is a power of lens having focal length

1. A. 100 cm✓
2. B. 10 cm
3. C. 1 cm
4. D. 1/10 cm

16. Real images formed by a single convex lens is always ..........

1. A. On the same side of the lens as the object
2. B. Inverted✓
3. C. Erect
4. D. Smaller than the object

17. Visual acuity recorded by Snellen's test chart is a measure of

1. A. Light sense
2. B. Form sense✓
3. C. Contrast sense
4. D. All

18. Subdivision of visual acuity for hyperacuity

1. A. Minimum visible
2. B. Minimum resolvable
3. C. Minimum discrininable ✓
4. D. None

Three subdivisions of visual acuity are:

• Minimum visible-detection of the presence of a visual stimulus.
• Minimum resolvable-ordinary visual acuity.
• Minimum discernible-hyperacuity.

20. unit of luminous flux

1. A. Lux
2. B. Lumens✓
3. C. Lambert
4. D. Foot candles

Lux is unit of illuminance, the total amount of light that falls on a surface

Lumens is unit of luminous flux, the total amount of light emitted in all directions. Lambert is one lumen per square cm. Foot candle is one lumen per square foot.

21. Hemeralopia is

1. A. Inability to see clearly in dim light
2. B. Inability to see clearly in bright light✓
3. C. Inability to see colour
4. D. Difficulty to read words

• Nyctalopia- Night Blindness
• Hemeralopia- inability to see clearly in bright light
• Achromatopsia- colour blindness
• Word Blindness- dislexia
• hemianopia- blindness in half field of vision
• Amblyopia- lazy eye

22. Amblyopia can occur in all except

1. A. Uniocular high myopia
2. B. Uniocular high hypermetropia
3. C. Uniocular high astigmatism
4. D. Uniocular aphakia✓

Aphakia is most commonly acquired, it will not cause amblyopia. Congenital aphakia can cause amblyopia, but it is a very rare condition.

24. All are causes of irregular astigmatism except

1. a. Pterygium
2. b. Keratoconus
3. c. Corneal scarring
4. d. Cataract surgery✓

Post operative astigmatism is usually regular

25. False regarding aphakia

1. a. High hypermetropia
2. b. Shallow anterior chamber✓
3. c. Complete loss of accommodation
4. d. Iridodonesis

Signs of aphakia

• Limbal scar in surgical aphakia
• Anterior chamber is deeperl.
• Iridodonesis - tremulousness of iris
• Pupil is jet black in colour.
• Purkinje’s image test shows only two images (normally four).
• Refraction reveals high hypermetropia.

26. Temporal crescent is seen typically in

1. a. astigmatism
2. b. hypermetropia
3. c. myopia✓
4. d. none of the above

27. Blurring of vision for near work occurs in

1. a. hypermetropia
2. b. presbyopia
3. c. both of the above✓
4. d. none of the above

Hypermetropes will accommodate for distance to see clearly. So, exessive

accommodation is needed for NV, that causes difficulty and blurring in near vision, especially in high hypermetropes. That's why hypermetropia is known as long sightedness.

28. Optical conditions of aphakia include all EXCEPT

1. a. loss of accommodation
2. b. astigmatism with the rule✓
3. c. enlargement of retinal image
4. d. Hypermetropia

Due to pressing of lids in vertical meridian the vertical curvature of cornea will be greater than horizontal. This causes a small astigmatism, resulting power will be -cyl@180 or +cyl@90. -cyl @180 or +cyl@90 is called as with the rule astigmatism. In surgical aphakia, because of the healing of scar vertical meridian becomes more flatter, resulting astigmatism will be +cyl@180. This astigmatism is against the rule.

29. Unilateral aphakia is best corrected by

1. a. contact lens
2. b. intraocular lens implant✓
3. c. Spectacles
4. d. none

30. Standard power of posterior chamber intraocular lens is

1. a. + 20 D✓
2. b. +10 D
3. c. + 5 D
4. d. + 15 D

31. Cylindrical lenses are prescribed in

1. a. presbyopia
2. b. astigmatism✓
3. c. myopia
4. d. squint

32. A newborn is invariably

1. a. hypermetropic✓
2. b. myopic
3. c. astigmatic
4. d. Presbyopic

33. Astigmatism is mostly a type of

1. a. axial ametropia
2. b. index ametropia
3. c. curvature ametropia✓
4. d. spherical aberration

34. Hypermetropia causes

1. a. divergent squint
2. b. convergent squint✓
3. c. both of the above
4. d. none of the above

35. In retinoscopy using a plane mirror with working distance 1m, when the mirror is tilted to the right the shadow in the pupil moves to the left in

1. a. hypermetropia
2. b. myopia more than –1 D✓
3. c. emmetropia
4. d. myopia less than –1 D

36. Patients with high myopia (>6D) are at a higher risk of

1. a ) Retinal detachment
2. b) Macular degeneration
3. c) glaucoma
4. d) All of the above✓

37. The bending of a beam of light when it passes obliquely from one medium to another is known as _______.

1. 1.reflection
2. 2.refraction✓
3. 3.dispersion
4. 4.deviation

38. Ray of light passes without deviation, if pass through

1. 1.optical centre
2. 2.focus
3. 3.centre of curvature✓
4. 4.pole

39. Convex lens always gives a real image if the object is situated beyond _______.

1. 1.optical centre
2. 2.centre of curvature
3. 3.focus✓
4. 4.radius of curvature

40. Parallel rays of light entering a convex lens always converge to _______.

1. 1.centre of curvature
2. 2.the principal focus✓
3. 3.optical centre
4. 4.the focal plane