Study On The Effect Of The Texture Of Stereograms' Dots On The Stereopsis Test

Objective To testify the practicability of the computer-stereogram that we made by ourselves, to study on the effect of the texture of the dots (irregular , quadrate, round)on the stereopsis test, and to provide the base for the stereograms' facture. Methods Three different stereograms are made of irregular , quadrate and round random-dots. First, according to the disparity of TNO stereopsis test, we get the values with the irregular random-dot stereogram. Select 34 amblyopic children aged from 5 to 9.Test their crossed disparity and uncrossed disparity stereoacuities with TNO at 40cm and the computer irregular random-dot stereogram at 170cm. Compare their values by the Wilcoxon ranking test. Then test the children's crossed disparity and uncrossed disparity stereoacuities with three different stereograms separately. Compare their values by the analysis of variance of random blocks design. Results 1.There are no differences between the irregular random-dot stereogram and TNO test in crossed disparity (P=0.2604, >0.05) or in uncrossed disparity (P=0.5350, >0.05). 2. In crossed disparity, the averages with the irregular , quadrate and round random-dot stereograms are 139.4148 " 81.2009 " , 133.2353 " 75.3867 " and 131.4706 " 74.5952 " separately . There is difference between the irregular and the quadrate random-dot stereogram: P=0.0329, <0.05, and there is difference between the irregular and the round random-dot stereogram(P=0.0181, <0.05), but there is no difference between the round and the quadrate random-dot stereogram( P=0.5356, >0.05). In uncrossed disparity, the averages with the irregular , quadrate and round random-dot stereograms are 191.4706 " 123.1440 " , 179.1176 " 110.1615" and 178.253" 99.0706" separately . There is difference between the irregular and the quadrate random-dot stereogram(P= 0.0262, <0.05), and there is difference between the irregular and the roundrandom-dot stereogram( P=0.0154, <0.05), but there is no difference between the round and the quadrate random-dot stereogram(P=0.5615, >0.05). Conclusions 1. The computer-stereogram that we made by ourselves is tested to have the similar practicability to TNO. 2. The texture of the random-dot stereogram's dots have effect on the amblyopic children's stereopsis tests. Among the three stereograms, the irregular random-dot stereogram is hardest, the round random-dot stereogram and the quadrate random-dot stereogram have no difference. When test the amblyopic children's stereoacuities, the regular random-dot stereogram is better.