Test 16  (Practical clinical refraction)
1. During clinical refraction:
a. accommodation results in a more myopic prescription

b. the visual acuity is measured binocularly for distance 
    and near

c. occlusion is recommended for patient with nystagmus to
    reduce the ocular movement

d. a high minus lens over the non-examining eye of a 
    patient with bilateral congenital nystagmus can reduce 
    the nystagmus

e. recent wearing of gas permeable lens may give 
    erroneous results 


2. The following tests depend on binocular vision:
a. Maddox rod

b. Maddox wing

c. Worth's four dots test

d. Duochrome tests

e. Bagolini's test

3. Fogging::

a. reduces or eliminates accommodation 

b. brings the image behind the retina

c. uses strong plus lenses

d. is achieved by adding minus sphere power to 
    plus corrections

e. is achieved by reducing minus sphere power in minus 


4. In objective refraction:
a. accommodation is stimulated if the patient stared at 
    the light from the retinoscope

b. 'with' motion occurs in high myope if the sleeve of the 
    retinoscope is placed in the plano mirror position

c. 'against' motion occurs in hypermetrope if the sleeve of 
    the retinoscope is placed in the concave mirror position

d. movement of the reflex increases as the neutralization 
    point is near

e. the power of the working distance lens in dioptres is 
    proportional to the working distance in metres

5. Using minus cylinder during refraction :

a. avoids stimulation of  accommodation in young 
    hypermetropic patients

b. may overcorrect hypermetrope in the elderly

c. may overcorrect hypermetrope in cycloplegic refraction

d. may undercorrect myope patients

e. is a major cause of spectacle intolerance

6. The following is the power cross of a patient examined at 2/3 meters 
    (before correcting for the working distance):

a. when a streak retinoscopy is used to neutralize the eye 
    at 30the power of the lens needed is +4.00

b. if the patient were to accommodate the power cross 
    will have a higher plus power

c. if a +5.00DS lens is placed in the trial frame; a 
    -1.00DC is required to neutralize the eye at 1200

d. the lens required for correcting this patient's refraction 
    can be +2.50/+1.00 X 30

e. the lens required for correcting this patient's refraction 
    if the working distance is 1/2 m can be 
    +3.00/-1.00X 120


7. In subjective refraction:
a. the spherical power should be tested before the cylinder

b. the axis of the cylinder should be verified before the 

c. Duochrome test should be only performed when the 
    spherical power is corrected to within 1 D of 

d. if the letters against the green background appear 
    clearer on the Duochrome test, more plus correction or 
    less minus correction is indicated.

e. Maddox rod test is useful in patients with manifest 

8. The interpupillary distance:

a. can be measured using the corneal reflex

b. can be measured by noting the distance between the 
    nasal limbus of one eye and the temporal limbus of the 

c. used in making spectacle is 1 mm less than the 
    anatomical interpupillary distance

d. for a patient with accommodative esotropia is the 
    distance between the two corneal reflexes without 
    spectacle correction

e. for a patient with intermittent exotropia is the distance
    between the two corneal reflexes when the two eyes 
    are in primary position


9. A 42 year-old myopic man recently changes his glasses and 
    find them uncomfortable despite having a visual acuity of 6/6 in 
     both eyes. The following may be responsible:
a. over-correction of myopia

b. onset of presbyopia

c. change of lens form

d. change of axis

e. decentring  of the lens


10. Regarding refraction in children:
a. myopia is more common than hypermetropia

b. refractive amblyopia can occur if there is more than 1 
    dioptre of hypermetropic anisometropia

c. increased accommodation is used by children to 
    overcome uncorrected hypermetropia

d. myopia tends to progress as the child grows older

e. correction of hypermetropia can reduce exophoria

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