Midterm Examination Name _____________________________
Vision Science 117
Spring 1996
Circle all correct answers on the answer sheet. More than one or none may be correct. When completed, retain this copy of the test and turn in your answer sheet.
GOOD LUCK
1. Which of the following motor disorders is in most urgent need of further diagnosis or treatment?
a. congenital disorder
b. developmental disorder
c. recently acquired disorder
d. motor anomalies associated with sensory disorders
2. Which of the following can be described as conjugate movements
a. an abduction of the right eye and adduction of the left eye
b. a levotorsion of the right eye and dextrotorsion of the left eye
c. an elevation of the right eye and depression of the left eye
d. an intorsion of the left eye and extorsion of the right eye
3. Which of the following classes of conjugate eye movements has the shortest latency?
a. saccades
b. pursuits
c. OKN
d. VOR
4. Which of the following are classified as image stabilizing eye movements?
a. saccades
b. pursuits
c. OKN
d. VOR
5. Which of the following prevents you from seeing your eyes move when you look in a mirror?
a. saccadic suppression
b. reversal of the reflected image from the mirror
c. blinks
d. long latency for saccades
6. Which of the following are tertiary eye positions?
a. primary
b. 5 deg left
c. 5 deg up and to the right
d. asymmetric convergence in elevated gaze
7. Which of the following can be used to quantify eye position?
a. horizontal rotation
b. vertical rotation
c. torsional rotation
d. oblique rotation
8. Which of the following coordinate systems describes the head movement of a horse?
a. Fick
b. Helmholtz
c. Listing
d. Hess
9. Which of the following coordinate systems are Cartesian?
a. Fick
b. Helmholtz
c. Listing
d. Hess
10 Which of the following coordinate systems have hyperbolic (curved) isoelevation lines on a tangent screen?
a. Fick
b. Helmholtz
c. Harms
d. Hess
11. Which of the following coordinate systems operates in the equatorial plane and has no false torsion?
a. Fick
b. Helmholtz
c. Harms
d. Hess
12. Which of the following laws states that the angle of ocular torsion in any direction of gaze is independent of the path the eye took to get to that position.
a. Listing's Law
b. Hering's Law
c. Donder's Law
d. Newton's Law
13. The isovergence surface
a. approximates the Veith-Muller circle
b. describes the locus of points that subtend a constant angle at the centrodes of the two eyes
c. describes the locus of points that stimulates equal-conjugate angles
of rotation of the two eyes
d. is an ellipse in the visual plane
14. Which of the following eye position measurement methods utilize entoptic phenomenon?
a. corneal reflection
b. Maxwell's Spot
c. Maddox rod
d. Haidinger's brushes
15. Which of the following catoptric images is used to quantify eye position in direct observation?
a. First Purkinje image
b. Second Purkinje image
c. Third Purkinje image
d. Forth Purkinje image
16. Which of the following pairs of axes is a correct definition of angle Kappa
a. Visual and Optical axes
b. Visual and Pupillary axes
c. Line of sight and pupillary axis
d. fixation axis and optical axis
17. Which of the following clinical objective recording techniques is most frequently used clinically?
a. EOG
b. Infra-red reflection
c. Video pupil monitor
d. Search coil
18. Which of the following Optometers presents a constant image size and has its secondary focal point coincident with the anterior nodal point of the eye?
a. Simple
b. Badal
c. Nagel
d. Third Purkinje
19. The Scheiner pupil
a. Was used to demonstrate the existence of accommodation
b. produces double perceived images of images focused behind the retina
c. produces double images of objects that are not conjugate to the retina
d. produces images of two pupils on the retina at all times
20 The Newtonian lens formula computes image vergence with respect to which of the following
a. The posterior focal point of any optometer lens
b. The anterior focal point of the eye for a Badal Optometer
c. The anterior nodal point of the eye for a Nagel Optometer
d. The principal plane of the simple optometer lens
21. Which of the following mechanisms of accommodation are used by the cat to control accommodation?
a. ramp retina
b. change corneal power
c. anterior-posterior translation of lens position
d. change index of refraction
22. Which of the following would occur if the index of refraction of the lens cortex increased to match the index of the nucleus.
a. The eye would become less myopic
b. The myodiopter would increase
c. light would be refracted more within the lens than at its surfaces
d. the lens would be more elastic
23. Which of the following structures are attached to the lenticular suspensory ligaments ?
a. The lens capsule
b. The ciliary processes
c. Bruchs membrane
d. The scleral spur
24. Which of the following changes occur in the lens during accommodation ?
a. the lens anterior-posterior thickness decreases
b. the third Purkinje image moves forward and decreases in size
c. the lens capsule thickness variations mold the anterior surface curvature
d. the lens is affected by gravity
25. Which of the following occur as a function of age and contributes to presbyopia
a. Lens diameter increase
b. The index of refraction becomes more uniform
c. The lens becomes less plastic
d. The space between the ciliary processes and lens equator increases
26. Which of the following contribute to night myopia?
a. chromatic aberration
b. Purkinje shift
c. Positive spherical aberration
d. Pupil dilation
27. Which of the Maddox-Heath components of accommodation are coarse adjusters?
a. Tonic
b. Proximal
c. Blur or optical reflex
d. Convergence
28. Which of the following could be used as odd-error information to control the direction of accommodation?
a. blur
b. chromatic aberration
c. astigmatism
d. temporal fluctuations of lens power
29. Which of the following factors will increase the depth of focus of the eye?
a. increased pupil size
b. decreased visual acuity
c. increased letter size for refractive evaluation
d. decrease aberrations of the eye
30. Which of the following contributes to the kertotic distribution of phorias in the general population?
a. prism adaptation
b. orthophorization
c. emmetropization
d. disparity vergence
31. Which is the most utilize Maddox component of convergence?
a. Tonic
b. Proximal
c. fusion or disparity
d. accommodation
32. Which form of vergence is most often accompanied by saccades that violate Hering's Law?
a. symmetrical convergence
b. symmetrical divergence
c. asymmetrical convergence
d. asymmetrical divergence
33. Which of the following have the shortest latency?
a. saccades
b. accommodation
c. convergence
d. pursuits
34. Which of the following describes the range of disparities that fusional vergence responds to?
a. Panum's fusional area
b. 2-4 degrees
c. 5-10 degrees
d. 10-40 degrees
35 Which of the following is true about the amplitude of the AC/A ratio?
a. The response ratio is greater than the stimulus ratio
b. The gradient measure is greater than the calculated measure
c. dynamic ratio is greater in response to fast than slow changes in accommodation
d. the AC/A ratio is greater than the ideal of 1 MA/D
36. The response AC/A ratio
a. is linear over its entire range
b. is highly adaptable
c. is increased by cycloplegic drugs
d. varies by several prism diopters from month to month
CALCULATIONS
37. (4 points) Calculate the age at which a person with a 20 cm working distance would be expected to become a functional presbyope using Hoffstetter's formula.
(4 points)What is this persons expected amplitude of accommodation at age 27 years?
38. ( 4 points) Calculate the AC/A of a patient with a 6 cm PD who had a distance phoria of 1 eso and a near phoria measured at 33 cm of 7 eso.
39. ( 4 points) Determine the gradient AC/A of the same patient when a plus 2 diopter lens is worn at the same near viewing distance the near phoria becomes 5 exophoric.
40. ( 4 points) Calculate the conjugate focus (CF) and accommodative response (AR) to an unknown test target distance measured with the stigmascope, given the following. Uncorrected refractive error is 2 D hyperopia, a minus one lens is before the eye and the stigma is set at 5 cm from a +10D Badal lens.
CF(D)=
AR(D)=
Vision Science 117 NAME__________________________
Midterm examination, Spring 1996
ANSWER SHEET
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11 a b c d 29 a b c d
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14 a b c d 32 a b c d
15 a b c d 33 a b c d
16 a b c d 34 a b c d
17 a b c d 35 a b c d
18 a b c d 36 a b c d
37.
age for functional presbyopia
amplitude of accommodation at age 27
38.
Calculated AC/A
39.
Gradient AC/A
40.
CF(D)=
AR(D)=