Amir Mohammad’s blindness and descend was mentioned in the beginning of nearly all sources discussing his imprisonment. However, the Beyhaqi history and Zeanolakhbar (Gardizi), the main works of the Ghaznavid dynasty do not mention these at all, thus the clarity of this matter is still left to be discussed. According to critics, it would be obvious that these two sources are provided by people with strong ties to the court of Gaznavid. Abolfazel-e Beyhaqi, one of the most outstanding historians and annalists of the court of Gazne in the 5th century, does not report on the subject of Amir Mohammad. The incident involving Amir Mohammad is only mentioned later on in literature, approximately from the 6th century. Therefore, the gaps between the early sources and later texts on the subject, cast doubts on the matter.In this paper the authenticity of the matter will be discussed by examining the quotations from available sources and foundations, to accept that Amir Mohammad had been blind in 1030; despite Beyhaqi’s silence on the event in the final part of Maso'ud’s regime. Yet this needs more valid sources, such have not been available so far. This paper examines the measure of valid references. However, the interpretation of those available references may shed some light on this issue.