Abstract
Purpose :
Model of stereometer 4D-Visus with an integral feedback is precise and effective when measuring and training both healthy and disordered stereovision in Z axis (depth). The purpose of this work is to improve and investigate the model and device precision not only in Z, but also in X and Y axes, and to determine their suitability for measuring and training individuals' abilities in 3D space and time.
Methods :
The method enables the measurement and training of 3D vision and activity for its precise and integral feedback between vision and coordinated movement of eyes, virtual objects and a hand in X, Y, and Z axes. The stereometer consists of a PC, an optical system and software (Fig.1, 2).
The projections of basic (BO) and test (TO) objects in 4D space - X, Y, Z axes and time, are shown on a screen. BO in 4D space is operated by the software and TO - by a testee. The precision of instant, mean and standard deviation of disparity as well as other characteristics of stereovision and activity are evaluated according to the coordinates of BO and TO in space and time.
The model was tested in the direction of one axis at a time. BO was moving in X, Y or Z axis for the same distance, basically with an amplitude A=2 cm. The object movement angle in the X and Y axes was changed from 1° to 3°, and in Z axis - about 0.5°-2°. 22 adult individuals participated in the research, including two individuals who had had their stereovision trained before.
Results :
It was established that precision of movement of the testees in X and Y axes are the same and approximately 3-5 times higher than in the direction of Z axis. The precision of movement in X and Y axes at T=20 s and A=2 cm was 0,08 cm on average and within the range T=5-40 s, and A=2-8 cm didn’t change significantly. Dynamic stereoacuity was 2-3’.
Optimal conditions to start researching and training 3D vision and activity are close to real life situations. The optimal parameters to eliminate strabismus and train stereovision were found to be the distance of 50-60 cm from the eyes to the screen, period of movement T=10-30 s, and its A=2-8 cm.
Conclusions :
The improved model and device of stereometer 4D-Visus is effective to measure and train the capacities of individuals in 3D space and time. The capacity of movement in X and Y axes is the same and several times more precise than in Z axis. Different individuals have the optimal parameters for 3D movement and vision precision and training.
This is a 2020 ARVO Annual Meeting abstract.