Emmetropization

Question 1

Which of the following statements about the distribution of refractive error AT BIRTH in full-term infants is NOT TRUE?

a. Very few infants (less than 5 percent) are myopic at birth.
b. Myopia is less prevalent in full term infants than in premature infants
c. The average refractive error is 2D hyperopia.
d. The distribution of refractive error is normal (Gauss).
e. There is a very large standard deviation 2-3D.

Answer 1

a. Very few infants (less than 5 percent) are myopic at birth.

Question 2

Which of the following optical parameters of the adult eye is not distributed normally, meaning it does not have a bell-shaped distribution?

a. Corneal power
b. Depth of the anterior chamber
c. Lens power
d. Lens thickness
e. Axial length

Answer 2

e. Axial Length

Question 3

Ignoring the sign of its coefficient, which of the following variables shows the greatest correlation with refractive error?

a. Corneal power
b. Depth of the anterior chamber.
c. Lens power
d. Axial length
e. Total refractive power

Answer 3

d. Axial Length

Question 4

In comparing refractive-correction distributions of adults to infants, the adult distribution

a. has a smaller variance.
b. is skewed towards myopia.
c. has an average which is shifted towards myopia.
d. all of the above are true.
e. none of the above are true.

Answer 4

d. All of the above are true

Question 5

Emmetropization was introduced to explain which of the following properties of the distribution of refractive error.

a. its skewness
b. its leptokurtosis
c. both of the above
d. the development of myopia during the school years
e. the prevalence of hyperopia in newborns

Answer 5

b. its leptokurtosis

Question 6

The age span where myopia typically develops is

a. birth to 6 years
b. 7-25 years
c. 26-40 years
d. 40-60 years
e. +60 years

Answer 6

b. 7-25 years

Question 7

At age six, a child is a +0.75D hyperope. By age thirty, refractive error is expected to have shifted towards

a. myopia
b. higher hyperopia
c. presbyopia
d. cataract formation
e. can not be reasonably predicted

Answer 7

a. myopia

Question 8

Which of the following statements about changes in refractive error with age is NOT TRUE?

a. In comparison to adults, there is little myopia for children entering elementary school.
b. Because of School Myopia, most children are myopic at the end of elementary school.
c. The average refractive error remains relatively constant from age 20 to age 40.
d. From age 40 to age 60, the average refractive error increases in the hyperopic direction.
e. After the age of 65, the average refractive error decreases towards myopia.

Answer 8

b. Because of School Myopia, most children are myopic at the end of elementary school.

Question 9

The dramatic increase in myopia among young Eskimos is most likely due to

a. abnormal growth of the eye due to extended darkness during winter months.
b. extended near point work associated with compulsory education.
c. excessive convergence of the eyes.
d. familial inheritance patterns.
e. recent changes in Eskimo diet.

Answer 9

b. extended near point work associated with compulsory education.

Question 10

According to Hirsch’s rules, what would be the adult refractive correction for a child who had an ocular Rx of 0 at age 6?

a. Emmetropic
b. Myopic
c. Hyperopic
d. Astigmatic
e. According to Hirsch, no prediction can be made

Answer 10

b. Myopic

Question 11

The ocular component whose adult distribution is skewed like that of the refractive error is

a. corneal power
b. lens power
c. equivalent power of the eye
d. depth of the anterior chamber
e. axial length

Answer 11

e. axial length

Question 12

The adult distribution of axial length suggests that the axial length of a 6D myopic eye is

a. shorter than almost all emmetropic eyes.
b. longer than almost all emmetropic eyes.
c. shorter than the average axial length but not particularly different than emmetropic eyes.
d. longer than the average axial length but not particularly different than emmetropic eyes.
e. the same as that of an emmetropic eye.

Answer 12

b. longer than almost all emmetropic eyes.

Question 13

Which of the following statements about emmetropization is TRUE?

a. It is a biological process, which regulates eye growth in order to reduce any refractive error.
b. It refers to any process, which corrects or reduces refractive error.
c. It is a surgical procedure for correcting refractive error.
d. It helps explain the skewness in the refractive error distribution.
e. It explains the development of refractive errors.

Answer 13

a. It is a biological process, which regulates eye growth in order to reduce any refractive error.

Question 14

The leptokurtosis in the refractive error distribution curve first appears

a. at birth
b. at age 1-2 years
c. at age 3-6 years
d. during the elementary school years
e. during late adolescence

Answer 14

b. at age 1-2 years

Question 15

Myopia may be related to all of the following except which one?
A. Near work
B. Form deprivation
C. Limited exposure to outdoor environments
D. Gene loci
E. Myopia epidemics

Answer 15

E. Myopia epidemics

Question 16

CHOOSE 2: When a distant object is imaged in front of the retina continuously with plus lenses a monkey’s eye must compensate by growing in the direction of 
A. myopia 
B. hyperopia
C. increased elongation
D. reduced elongation

Answer 16

B. hyperopia

D. reduced elongation

Question 17

. Form deprivation Myopia (FDM) is a local and regional mechanism which means that all of the following are true except which one?

a. it does not require that the visual signal leave the eye
b. it does not require sympathetic or parasympathetic input to the eye.
c. local deprivation to a portion of the eye creates local elongation and myopia.
d. it can occur when properly corrected refractive error is different in each eye

Answer 17

d. it can occur when properly corrected refractive error is different in each eye

Question 18

. All of the following describe how peripheral retinal blur and defocus relates to myopia except which one?

a. those with moderate myopia may have a greater degree of relative peripheral hyperopia b. those with moderate myopia may have a more spherical ocular shape
c. a steep peripheral retina creates hyperopic peripheral defocus leading to myopic shift
d. overall retinal hyperopic signal induces axial growth and myopic shift

Answer 18

b. those with moderate myopia may have a more spherical ocular shape

Question 19

All of those below except which one has been found in some studies with weak evidence that axial elongation and thus myopia progression can be reduced by…

a. decreasing ambient lighting at night
b. rearing chicks in a 12 hour on/off light/dark cycle rather than a continuous 24 hour light-on cycle
c. wearing bifocals instead of single vision near glasses
d. Orthokeratology (OK) or corneal reshaping therapy (CRT) using contact lenses to flatten the cornea.
e. Wearing minus lenses in excess of one’s refractive correction on a continuous wear basis

Answer 19

e. Wearing minus lenses in excess of one’s refractive correction on a continuous wear basis