Dyslexia is one of the most common specific learning disorders. By enrolling into the school system, children with dyslexia encounter obstacles in acquiring academic skills which are essentially bellow skills expected in a particular chronological age. Because of that, many researches are dedicated to finding the cause of difficulties in decoding and techniques which would facilitate reading, understanding and writing of people with dyslexia. The goal of this diploma thesis was to examine the influence of graphical adjustment of the text based on larger font size, wider space between letters and other known adjustment on the speed of reading as the aspect of reading technique and on understanding with students with diagnosed dyslexia. The research was conduced on twenty fourth grade students, ten of which are diagnosed with dyslexia, and the others without reading and writing difficulties. For the purpose of the research two equally difficult narrative texts were designed, one of which was graphically adjusted. The questions following texts tested the understanding of previously read in the selected sample. Data analysis revealed statistically significant difference between the two groups of data subjects in the speed of reading of the two differently graphically adjusted texts, but also in their understanding. Concerning the group of children with diagnosed dyslexia, analysis showed statistically significant difference in the number of reading mistakes with two differently graphically adjusted texts, as in their understanding. Concerning the children without reading difficulties, analysis showed statistically significant difference in understanding of two differently graphically adjusted texts. The results of this research coincide to a large extent with foreign research concerning graphical adjustment of text.