Optometry and Ophthalmology MCQ, Part-08

01. A Snellen visual acuity of 20/20 is equivalent to which of the following logMAR values?

a. 1.00
b. 0.00✓
c. 10.00
d. 0.10

logmar value of 6/6 vision is 0.0, but decimal value of 6/6 vision is 1.0, and logmar value
of 6/60 vision is also 1.0

02. Refractive power of anterior corneal surface is

a. 53 D
b. 48 D✓
c. 43 D
d. 38 D

We know power of cornea is +43D, but power of anterior corneal surface is +48D and
posterior corneal surface -5.0 D so totally power of cornea is +43D.

03. Far point of myopic eye is

a. Behind the retina
b. On the retina
c. In Front of the retina
d. In Front of the cornea✓

We know parallel rays of light focus in front of retina in myopic eye. But far point of myopic eye is a finite point in front of the cornea, that's why myopes see near without accommodation.

04. Dynamic Retinoscopy gives an objective refraction for

a. Near vision✓
b. Distance vision
c. Both
d. None

05. Skiascopy is another name for

a. Distant direct ophthalmoscopy
b. Retinoscopy✓
c. Perimetry
d. Gonioscopy

06. Types of regular astigmatism are : (I). Simple astigmatism (II). Compound astigmatism (III). Mixed astigmatism

A. (I)&(II)
B. (III) only
C. All the above✓
D. None

07. 1mm increase or decrease in radius of curvature is equivalent of how many diopters

A. 1 D
B. 3 D
C. 6 D✓
D. 0.5 D

1mm change in axial length make 3D.

08. Physiological tone of ciliary muscle is

A. +1 diopters✓
B. +3 diopters
C. +0.5 diopters
D. +14 diopters

09. Types of manifest hypermetropia are: I) total (II) facultative (III) absolute (IV) Latent

A. (I) & (II)
B. (II) & (III)✓
C. (I), (II) & (III)
D. (II) & (IV)

10. Newborn eye is

A. Hypermetropic✓
B. Myopic
C. Astigmatic
D. Emmetropic

11. Visual field is largest for which colour

A. Blue
B. Green
C. Red
D. White✓

12. Visual field is smallest for which colour

A. Blue
B. Green✓
C. Red
D. White

13. How much angle should each letter substend at the nodal point of the eye at the given distance in the snellen's chart

A. 1 minutes
B. 5 minutes✓
C. 1 degrees
D. 5 degrees

14. Image magnification in direct ophthalmoscopy

A. 5 times
B. 10 times
C. 15 times✓
D. 20 times

15. In direct ophthalmoscopy the image in a myopic eye is

A. Smaller
B. Bigger✓
C. Same size
D. Any of the above

In myopia distance between nodal point and retina increases, so image appears bigger

16. Which of the following is true regarding the image formed by a prism?

a. It is virtual and displaced towards the apex✓
b. It is real and displaced towards the apex
c. It is virtual and displaced towards the base
d. It is real and displaced towards the base

The image formed by a prism is erect, virtual and displaced towards the apex of the prism Please note, if asked direction of deviated rays, it's towards the base.

17. A glass prism (refractive index 1.5) of 20 prism dioptres deviates an incident

ray of light through:
a. 5 degrees
b. 10 degrees✓
c. 20 degrees
d. 40 degrees

For a glass prism of refractive index 1.5: Angle of deviation = refracting angle /2; D=a/2; Therefore, 1 prism dioptre power produces an angle of deviation of 0.5 degrees, and a 20-dioptre powered prism deviates light through 10 degrees.

18. For a convex lens, placing an object inside the first principal focus (F) results in an image that is:

a. Enlarged, inverted and real
b. Enlarged, erect and real
c. Enlarged, inverted and virtual
d. Enlarged, erect and virtual✓

In the above position, convex lens act as a magnifying lens.

19. If a 10-dioptre concave lens is decentered by 2 cm temporally, this will result In a:

a. 5 prism dioptre base-in prism
b. 5 prism dioptre base-out prism
c. 20 prism dioptre base-in prism✓
d. 20 prism dioptre base-out prism

Prismatic power = lens power x decentration (in cm) In convex lens, prism base is in the same direction as the movement of lens, and in concave base will be opposite to the direction of decentralisation.

20. Which colour of light deviates maximum in the dispersion of white light by prism?

a. Violet✓
b. Blue
c. Green
d. Red

Please note Wavelength is inversely proportional to the deviation, Red light has longer wavelength and thus least deviated.

21. The image of an object formed by reflection at a plane surface is not:

a. Erect
b. Virtual
c. Real✓
d. Laterally inverted

22. The catoptric image formed from which of the following is inverted?

a. Anterior corneal surface
b. Posterior corneal surface
c. Anterior lens surface
d. Posterior lens surface✓

Images formed from the reflecting surfaces of the eye are termed catoptric images. These surfaces are the anterior (I) and posterior (II)corneal surfaces and the anterior (Ill) and posterior (IV) lens surfaces. Images I, Il and III are erect and virtual. Image IV is real and inverted.

23. Hruby lens used for ophthalmoscopy is a?

a. Convex lens
b. Concave lens✓
c. Cylindrical lens
d. None

Hruby lens is a Plano-concave lens with diopteric power of -58.6D

24. Total internal reflection occurs if the incident ray strikes the interface of media at:

a. An angle less than the critical angle
b. The critical angle
c. An angle greater than the critical angle✓
d. 90 degrees.

25. An object located between the centre of curvature and principal focus of aconcave mirror is:

a. Diminished
b. Virtual
c. Erect
d. Real✓

between the centre of curvature and principal focus of a concave mirror image is real, enlarged, inverted and lies outside the centre of curvature.

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