Selective placement for the handicapped : information for the placement of disabled applicants in competitive employment / War Manpower Commission, United States Employment Service.

Date:: 1945

Credit: Selective placement for the handicapped : information for the placement of disabled applicants in competitive employment / War Manpower Commission, United States Employment Service. Source: Wellcome Collection.

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$in the field of vision. In some cases all close work may be forbidden. In addi- tion, high myopia tends to rule out strenuous activities (heavy lifting, pushing, pulling, jumping, or running) which might cause detachment of the retina (blindness). D. Miscellaneous Defects 1. Color-blindness This is not a disease but an imper- fect functioning of the retina which leads to color blindness. The most com- mon type is red-green loss, i. e., inability to distinguish between the two. The condition is usually congenital and af- fects males almost exclusively. Appli- cants with color-blindness require Se- lective Placement only when color dis- crimination is a necessary part of the job sought and a substitute means of distinguishing must be found. 2. Nystagmus This is a continuous jerking move- ment of the eyeball due to a nervous twitch. It is usually associated with congenital disease, or may develop from constant exposure to poor lighting. Vi- sion may be impaired because the eyes cannot remain still long enough to focus on an object. Work requiring steady directing of eyes on one spot may be unsuitable. E. Measuring the Functional Effici- ency of the Eye and Relation to Selective Placement 1. Acuity and Evaluation Placement of persons with a visual handicap depends upon the degree of vision after maximum correction, if correctable. The Snellen scale of grad- uated rows of letters is the one most frequently used to measure visual acu- ity. Persons are seated 2) feet from the chart. The normal person reads down to the line marked 20, this being repre- sented at 20/20. A reading of 20/50 “means that the tested individual sees at 20 feet what a normal sighted person sees at 50. These notations are not fractions, al- though written in similar form. To convert Snellen quotations into per- centage of visual efficiency the follow- ing table may be used: Visual Visual acuity efficiency Snellen in percent 20/20... 100 20/25... 95.6] Normal (with best 20/30-.. 91.4] correction) unless 20/40... 83.6/ corrected from 20/50... 76.5] 20/400 or worse. 20/60... 69.9} ° 20/70... 63.8 20/80... 58.5 20/90... 53.4]Impaired or de- 20/100._. 48.9] fective vision 20/120... 40.9( (with best cor- 20/140... 34.2] rection). 20/160... 28.6 20/180... 23.9 20/200... 20.0 20/220... 16.7 Industrial] y}20/240__. 14.0 blind (with best (20/260_.. 11.7 correction). 20/280__...9.8 a My ene ae 20/340_____5.7 riba Dag 20/380____- 4.0 : 20/400. ....3.3 20/500_..-- 1.1 20/600. ....0.6 20/800 _--- 0.1 Percentage rating is often preferred as & measure of vision. Most States accept 20/200 or less in the better eye after maximum correction as the thresh- old of blindness. Defective vision requiring Selective Placement ranges from 20/70 (64 percent) to 20/180 (23.9 percent) with best correction’ in one or both eyes. Vision of 20/400 or worse corrected to normal range (20/20—20/60) should also be deemed a handicap because of the high myopia. Applicants with visual acuity of 49 percent or less are usually classified as It is important that near vision be tested for those whose work is done at close range if they have scars on the cornea or, for any other reason, have$