Dissertations and Theses @ UNI


Open Access Thesis


Vision disorders in children; Vision -- Testing; Head Start programs -- Iowa;


This study was conducted to determine the incidence of visual anomalies, that are undetected by the present screening in the Head Start preschool population, as measured by the Keystone Vision Screening VS-11 (Keystone). A further aim of this study was to determine the relationship between Keystone screening results and performance on the subtests of the Chicago Early Assessment. The sample used for this study consisted of 74 Head Start preschool students enrolled in the Black Hawk-Buchanan Head Start program during the spring of 1988. The students were from nine different classrooms within the center. Their ages ranged from four to six years. Permission was granted by the Black Hawk-Buchanan Head Start Board to conduct the study and approximately 150 permission notes were sent home with the students asking parents to allow their children to participate. A total of 79 responses were returned, three of which were negative. Two of the children, for whom permission was granted, were not included in the study because of absence on the screening days. Records were examined for each subject to obtain results of the Parsons Visual Acuity Test (PVAT), and the Cover Test which were done by the nurse at Head Start; and the scores achieved on the Chicago Early Assessment subtests which were given by the children's classroom teacher. The sample was not random and consisted of children in nine classrooms at one Head Start center. The Keystone recommends retesting children who fail, however, that was not possible during this study. The referral rate of the Keystone was computed and compared to the referral rate of the present Head Start battery. The Keystone had a referral rate of 70% and the present Head Start battery had a referral rate of 7%. The disagreement rate between the two tests was 66%. Those who were referred for far point acuity and phoria by the Keystone were compared with those referred by the PVAT and the Cover Test. The Keystone identified 23 children for far point acuity problems whereas the PVAT identified only two, both of whom were also identified by the Keystone. The two tests had a 72% agreement rate. The Cover Test identified three children whereas the Keystone identified 20. Two of the children identified by the Cover were not identified by the Keystone. The two tests had a 70% agreement rate. The incidence of referrals by the Keystone for the following visual anomalies was computed: refractive errors, at near point (49%) and at far point (31%); lateral phoria, at near point (18%) and at far point (8%); vertical phoria, at near (16%) and at far (11%); and suppression at near (36%) and far (41%). Chi square tests of independence were done to determine if children who were referred for visual anomalies had a greater frequency of low scores on the subtests of the Chicago Early Assessment. Referral for visual anomalies was not found to be statistically significant in regard to low performance on the Gross Motor, or Memory subtests of the Chicago. Children referred for visual acuity problems both in general and at near and far, and those referred for suppression had a significantly higher frequency of low scores on the Fine Motor subtest. Those referred for far point acuity problems also had a significantly greater frequency of low scores on the Visual Discrimination subtest. Of those referred for suppression a significant number also scored low on the language subtest.

Year of Submission


Degree Name

Specialist in Education


Department of Educational Psychology and Foundations

First Advisor

Barry J. Wilson

Second Advisor

Donna B. Raschke

Third Advisor

Ned Ratekin


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