Perceptualand Motor Skills, 1990, 71, 1055-1058.
O Perceptual and Motor Skills 1990
STEREOSCOPIC EYE EXERCISES A N D VISUAL ACUITY' DAVID I. LASKY AND ANN M. LASKY Lebanon Valley College Summary.-The present study was done ro ~nvestigatethe effects of stereoscopic eye exercises on visual acuity, testing 20 college students (9 men and 11 women, ages 18 to 35 yr.). Visual acuity was assessed before and after the exercises through six tests: far vision-both eyes, right eye, left eye; and near vision-both eyes, right eye, left eye. Statistically significant improvements were found on five of the six pretestposrtest comparisons: far vision-both eyes, right eye, and left eye; and near visionboth eyes, right eye, and left eye. Changes in far vision, right eye only approached significance. Limitations of the present study were discussed, and recommendations for research were presented.
This study was prompted by experiences with a son who was said to need glasses by school staff, but after having practiced eye exercises with a stereoscope, when examined by an ophthalmologist, was 201/16' for near and far on tests for both eyes, right eye, and left eye. Examination of published sources gave information from uncontrolled observations; few experiments appear to have been undertaken. The sources included work by Spoerel (1982) who described a visit to China in 1974 where children were taught eye exercises in the classroom for the purpose of prevention of weaknesses in coordination and improvement of vision and adaptation. Spoerel states "I don't know whether it is statistically possible, or has been tried, to demonstrate that school children who do these exercises regularly, have better eyesight-or that there are fewer cases of strabismus or myopia (nearsightedness) amongst them" (Spoerel, 1982, p. 71). Rosanes-Berrett (1974) with the help of Frederick Perls, combined Gestalt psychotherapy with sight-training techniques. She reported seven cases in which clients' vision improved using Dr. Horatio Bates's techniques of vision therapy which required a machine that resembled a stereoscope. Also, Peppard (1940) advocated treatment for strain, presbyopia, and farsightedness, through eye exercises. Seiderman and Schneider (1988) described improving sports performance through visual training (drills and exercises). Karatz (1975) gave documentation critical of the Bates method of eye exercises as a means of improving acuity. Matlin (1988) also questioned Bates's views that improvement occurs through changes in eye muscles. The present authors on the basis of a case study approach based on one subject, decided to test the effects of stereoscopic exercises in a more sys-
'Please direct correspondence to David Lasky, Psychology Department, Lebanon Valley College, Annville, PA 17003.
tematic fashion. The purpose of the present study was to test the hypothesis that stereoscopic eye exercises will improve visual acuity.
Subjects The subjects were 9 male and 11 female college students who ranged in age from 18 to 35 yr. Initially they were given a visual acuity test. The criterion for selection was for the subjects to have either near or far visual acuity less than 20'/201. Materials Bausch and Lomb Vision Tester.-This is a stereoscopic machine which was used for the six tests of visual acuity: both eyes, right eye, and left eye at both near and far testing distances. The far tests are at an optical distance of 20' and the near tests are at an optical distance of 14". Each test has 12 targets of progressive difficulty over a range equivalent to Snellen ratings of 20J/200' to 201/17'. The target area consists of a checkerboard which may be located in any of the four corners of a diamond-shaped figure (top, bottom, right, left). Stereoscope.-An optical instrument used in studies of depth perception, has a pair of prisms so arranged that each displaces a picture presented to each eye. The two pictures taken from slightly different angles converge and the subject perceives the picture as having depth. Twenty black and white cardboard cards, 3 in. high and 6 in. wide, were used. O n 13 of the cards were words, six had pictures and one had numerical information. The cards are designed so that, when placed into the stereoscope, the eyes must converge the left and the right images to form one image. These images, taken from slightly different viewpoints, require the subject use both eyes to view the information on each card accurately, and on all of the cards except the last two only partial information was presented to each eye. Procedure Each subject was given a pretest and a posttest on the Vision Tester to assess visual acuity. Six frames were used: three frames (both eyes, right eye, left eye) for near vision and three for far vision. I n each frame the subjects were shown 12 targets with one checkerboard area on each target. The subject was to state the location of the checkerboard pattern on the card, using the words top, bottom, left or right. The number of checkerboards correctly identified was the score for that frame. Following the pretest, the subjects did the stereoscopic eye exercises, each day, for 8 to 10 days. O n the first day each subject looked at each of the 20 cards while the experimenter explained the nature of the information on the card. After the initial day the subjects worked at their own rate on the eye exercises. They were told to
1057
EYE EXERCISES
bring the information into sharp focus and then move the card closer and further away and see how far they could move the card and stiU keep it in focus. The task took the subjects 10 to 15 rnintes per day.
RESULTSAND DISCUSSION A t test for correlated data was used to compare the visual acuity of the subjects before and after the stereoscopic eye exercises. The dependent variable measure was the number of targets correctly identified on each of the six tests of visual acuity. Five of the six pretest-posttest comparisons by Student t were statistically significant; see Table 1. The significant differences were in far vision for both eyes where the mean increased from 4.8 to 5.9 and for the left eye where the mean number of correctly identified targets went from 4.3 to 5.2. For near vision and both eyes the mean number of targets identified increased significantly from 8.8 to 10.0 ( p< .01), for the right eye the mean increased from 8.4 to 9.0 ( p< .01), and for the left eye the pretest-posttest comparisons improved from 8.2 to 8.8 (p
O Perceptual and Motor Skills 1990
STEREOSCOPIC EYE EXERCISES A N D VISUAL ACUITY' DAVID I. LASKY AND ANN M. LASKY Lebanon Valley College Summary.-The present study was done ro ~nvestigatethe effects of stereoscopic eye exercises on visual acuity, testing 20 college students (9 men and 11 women, ages 18 to 35 yr.). Visual acuity was assessed before and after the exercises through six tests: far vision-both eyes, right eye, left eye; and near vision-both eyes, right eye, left eye. Statistically significant improvements were found on five of the six pretestposrtest comparisons: far vision-both eyes, right eye, and left eye; and near visionboth eyes, right eye, and left eye. Changes in far vision, right eye only approached significance. Limitations of the present study were discussed, and recommendations for research were presented.
This study was prompted by experiences with a son who was said to need glasses by school staff, but after having practiced eye exercises with a stereoscope, when examined by an ophthalmologist, was 201/16' for near and far on tests for both eyes, right eye, and left eye. Examination of published sources gave information from uncontrolled observations; few experiments appear to have been undertaken. The sources included work by Spoerel (1982) who described a visit to China in 1974 where children were taught eye exercises in the classroom for the purpose of prevention of weaknesses in coordination and improvement of vision and adaptation. Spoerel states "I don't know whether it is statistically possible, or has been tried, to demonstrate that school children who do these exercises regularly, have better eyesight-or that there are fewer cases of strabismus or myopia (nearsightedness) amongst them" (Spoerel, 1982, p. 71). Rosanes-Berrett (1974) with the help of Frederick Perls, combined Gestalt psychotherapy with sight-training techniques. She reported seven cases in which clients' vision improved using Dr. Horatio Bates's techniques of vision therapy which required a machine that resembled a stereoscope. Also, Peppard (1940) advocated treatment for strain, presbyopia, and farsightedness, through eye exercises. Seiderman and Schneider (1988) described improving sports performance through visual training (drills and exercises). Karatz (1975) gave documentation critical of the Bates method of eye exercises as a means of improving acuity. Matlin (1988) also questioned Bates's views that improvement occurs through changes in eye muscles. The present authors on the basis of a case study approach based on one subject, decided to test the effects of stereoscopic exercises in a more sys-
'Please direct correspondence to David Lasky, Psychology Department, Lebanon Valley College, Annville, PA 17003.
tematic fashion. The purpose of the present study was to test the hypothesis that stereoscopic eye exercises will improve visual acuity.
Subjects The subjects were 9 male and 11 female college students who ranged in age from 18 to 35 yr. Initially they were given a visual acuity test. The criterion for selection was for the subjects to have either near or far visual acuity less than 20'/201. Materials Bausch and Lomb Vision Tester.-This is a stereoscopic machine which was used for the six tests of visual acuity: both eyes, right eye, and left eye at both near and far testing distances. The far tests are at an optical distance of 20' and the near tests are at an optical distance of 14". Each test has 12 targets of progressive difficulty over a range equivalent to Snellen ratings of 20J/200' to 201/17'. The target area consists of a checkerboard which may be located in any of the four corners of a diamond-shaped figure (top, bottom, right, left). Stereoscope.-An optical instrument used in studies of depth perception, has a pair of prisms so arranged that each displaces a picture presented to each eye. The two pictures taken from slightly different angles converge and the subject perceives the picture as having depth. Twenty black and white cardboard cards, 3 in. high and 6 in. wide, were used. O n 13 of the cards were words, six had pictures and one had numerical information. The cards are designed so that, when placed into the stereoscope, the eyes must converge the left and the right images to form one image. These images, taken from slightly different viewpoints, require the subject use both eyes to view the information on each card accurately, and on all of the cards except the last two only partial information was presented to each eye. Procedure Each subject was given a pretest and a posttest on the Vision Tester to assess visual acuity. Six frames were used: three frames (both eyes, right eye, left eye) for near vision and three for far vision. I n each frame the subjects were shown 12 targets with one checkerboard area on each target. The subject was to state the location of the checkerboard pattern on the card, using the words top, bottom, left or right. The number of checkerboards correctly identified was the score for that frame. Following the pretest, the subjects did the stereoscopic eye exercises, each day, for 8 to 10 days. O n the first day each subject looked at each of the 20 cards while the experimenter explained the nature of the information on the card. After the initial day the subjects worked at their own rate on the eye exercises. They were told to
1057
EYE EXERCISES
bring the information into sharp focus and then move the card closer and further away and see how far they could move the card and stiU keep it in focus. The task took the subjects 10 to 15 rnintes per day.
RESULTSAND DISCUSSION A t test for correlated data was used to compare the visual acuity of the subjects before and after the stereoscopic eye exercises. The dependent variable measure was the number of targets correctly identified on each of the six tests of visual acuity. Five of the six pretest-posttest comparisons by Student t were statistically significant; see Table 1. The significant differences were in far vision for both eyes where the mean increased from 4.8 to 5.9 and for the left eye where the mean number of correctly identified targets went from 4.3 to 5.2. For near vision and both eyes the mean number of targets identified increased significantly from 8.8 to 10.0 ( p< .01), for the right eye the mean increased from 8.4 to 9.0 ( p< .01), and for the left eye the pretest-posttest comparisons improved from 8.2 to 8.8 (p
