Being dyslexic is a challenge. Use the term respectfully and without implying fault. My friend is dyslexic, so she uses different techniques to read effectively.
Pro Tip 2/3
Not Intellectual
Dyslexia does not affect intelligence. Avoid making assumptions about someone's intellect. Even though he's dyslexic, he's one of the top students in his math class.
Pro Tip 3/3
Avoid Stereotypes
Each dyslexic person's experience is unique. Descriptions should be individualized, not generalized. She's dyslexic, but her ability to understand complex concepts is amazing.