Further observations of dyslexia patients with prism correction

Report on 370 dyslexics, whereof 281 can be evaluated. The heterophoric cases were all corrected by Haase's method of prismatic binocular full correction. There are mainly esophorias but only little exophorias and strabisms. 3% are orthophoric. Visual acuity improved as well as sensory adaptations. The latter were mainly fixation disparities II. 82 operated cases resulted in a residual angle of 3+/-3 prism-diopters measured by Polatest. The influence on dyslexia is very good in 11%, good in 60%. 17% showed no influence on dyslexia but got rid of asthenopic symptoms. Only 12% failed. Good results are seen already after three months up to one year and in some cases even after 2 or 3 years. As optical and surgical corrections do not heal the dyslexia, it is discussed how to explain the obtained good results. The author's opinion is that prismatic corrections may save energy as the patients have no longer to compensate their heterophoria themselves. Thus they dispose on more energy e.g. for understanding of the text they are reading.