Prelim- Chapter 3

Question 1

Two assumptions regarding visual problems commonly encountered are:

Answer 1

that all visual problems are problems of acuity

that when the refractive error is corrected, all visual problems must cease.

Question 2

is caused by erroneous visual behavior that arises from the stresses imposed upon man because of the socially compulsive, near-centered task.

Answer 2

visual problem

Question 3

is a decrement in visual performance which is not acceptable to the patient or to his social-economic environment.

Answer 3

visual problem

Question 4

visual problem cannot exist in isolation; it can only be measured in relationship to the environmental demand

Question 5

Types of Visual Problems. (4)

Answer 5

A. Those who have lost acuity:
(1) distant (myope, amblyope, absolute hyperope, astigmat, squinter).
(2) near (presbyope).

B. Those who have uncomfortable vision (anisometrope, emmetrope, orthophore, minus projection).

C. Those who have unsatisfactory achievement (retarded reader, non-reader, unsatisfactory industrial producers).

D. Cosmetic reasons (squinter).

Question 6

The Development of the Visual Problem.

continuous concentration within a restricted area of movement, in a two-dimensional plane, that creates visual problems at near-point.

Question 7

Three types of functional visual changes can result from this impact between visual task and organism

Organisms:

Answer 7

1. The adventitious myope:
   (a) ablates acuity at far;
   (b) changes the mechanism of accommodation;
   (c) attains a high order of achievement at near.
2. The adventitious strabismic:
   (a) ablates binocularity;
   (b) changes the mechanism of convergence;
   (c) attains a satisfactory visual adaptation.
3. The low achiever:
   (a) retains acuity and binocularity;
   (b) does not change in the accommodative or convergence mechanism;
   (c) remains on a low level of visual achievement.

Question 8

The various body systems have a certain latitude of performance which will allow adaptation to occur so that the effect of the change in the environment can be mini-mized.

if the environmental change is of such a magnitude that it exceeds the latitude of performance, very serious consequences will ensue.

Question 9

The primary characteristic of any living system is its ability to adapt to changes in environmental demands.

It is these adaptative changes which modify the organism.

Question 10

Myopia is seldom developed under ages 10 to 12 except in very special cases.

Question 11

is an individual who had standard acuity at far, and lost it, but to whom it can be restored by means of a minus lens.

Answer 11

adventitious myope

Question 12

has made an extreme adaptation in binocularity in order to obtain increased eff-ciency at near. These individuals will usually have excellent reading rates and comprehension and seldom complain of discomfort,

Answer 12

adventitious squinter /strabismic

Question 13

These individuals usually have no symptoms of visual discomfort, for discomfort occurs when the level of achievement is unsatisfactory to the organism.

Answer 13

The Retarded Reader (poor achiever).

Question 14

The majority of the patients seeking optometric assistance do so because of the subjective complaint of visual discomfort.

Answer 14

Ocular Fatigue.

Question 15

eye muscles get “tired.”

when the nerve is stimulated and the contraction occurs

Answer 15

Ocular fatigue

Question 16

The physiological arrangement is organized for prolonged activity without fatigue.

Question 17

“Fatigue is the decreased capacity for doing work as a direct result of having worked; the amount of decrement varies with the duration, rate and intensity of the work, and with the initial strength or capacity of the organic mechanisms involved.’

Question 18

“Fatigue is characterized by:

Answer 18

a.) a decreased capacity for work, known as work decrement;
b.) modification in the physiological state of the individual;
c.) a feeling of weariness.”

Question 19

Measuring the Visual Problem. The amount of refractive error does not correlate well with either the degree of visual problem or the amount of visual discomfort.