Myasthenia Gravis (MG) is an autoimmune disorder, which may lead to paralysis and even death if not treated on time. One of its primary symptoms is severe muscular weakness, initially arising in the eye muscles. Testing the mobility of the eyeball can help in early detection of MG. In this study, software was designed to analyze the abil-ity of the eye muscles to focus in various directions, thus estimating the MG risk. Pro-gressive weakness in gazing at the directions prompted by the software can reveal ab-normal fatigue of the eye muscles, which is an alert sign for MG. To assess the user’s ability to keep gazing at a specified direction, a fuzzy algorithm was applied to images of the user’s eyes to determine the position of the iris in relation to the sclera. The re-sults of the tests performed on 18 healthy volunteers and 18 volunteers in early stages of MG confirmed the validity of the suggested software.