Did Leonardo da Vinci have dyslexia and did it boost his brilliance?

PHILADELPHIA (WPVI) -- On this 500th anniversary of Leonardo da Vinci's death, a local doctor says the artistic genius probably had dyslexia and that may have helped his creativity.

Dr. Salvatore Mangione of Jefferson University's Sidney Kimmel Medical College, says da Vinci could write perfectly in mirror image, yet his spelling and word composition were terrible.

He also drew a lot but wrote very little text, an indication he was uncomfortable writing.

One sculpture of a young da Vinci shows misaligned eyes suggesting he didn't have 3D vision.

"Paradoxically, you're going to be better suited to transport 3D reality onto the 2D page, so you are more likely to become a visual artist, and less likely to become a good reader," says Dr. Mangione.

Dr. Mangione says Thomas Edison, Sylvester Stallone, and Steven Spielberg are among other highly creative people with similar eye defects and either diagnosed or probable dyslexia.

Stallone was diagnosed as a child, while Spielberg was not diagnosed until he was 60.

Scholars are still debating whether Edison was dyslexic.

However, all had trouble with school, being referred to in terms like "addled" or "retarded."

Dr. Mangione has authored several articles on da Vinci. His most recent was just published in the American Journal of Medicine.