Q. Is a blind person permitted to read a Haftarah from a Braille text?
A. There is a general rule that the Written Torah must not be read from memory but from a Torah scroll. The Magen Avraham (OH 49:1) says that this prohibition is relaxed in order to allow a blind person to study Torah, but for the public reading of the Torah a scroll must be used. Hence a Bar-Mitzvah may say the Maftir blessings by heart or from a Braille text, but someone else must read the actual Maftir from the scroll.
In places where the Haftarot are read from a scroll, a Haftarah may not be read by heart or from Braille. In synagogues where a printed text is used for the Haftarot, a Bar-Mitzvah may recite the Haftarah from memory or from Braille, but some authorities prefer that the Haftarah be read a second time, before or after the Bar-Mitzvah boy, using a written text. (See J. David Bleich in Tradition, Vol. 17 No.2, Spring 1978, pp. 96-99).