Recent research on iStimulation: Research on iPad Apps for Children with Visual Impairments from Laura Campaña, Director of Infant & Early Childhood Program at Junior Blind of America.
Campaña and her team were investigating "the use of the Apple iPad as a means to:
Particularly useful for classroom teachers of students with special education needs who may be looking at how to collect useful data as part of an inquiry process into the effectiveness of particular apps in raising student achievement.
I have linked the article to the Paths to Literacy website rather than directly to the PREZI of the research, as it is also a rich resource if you have a student with a visual impairment in your class and/or you are interested into alternative approaches to supporting learners.