No one knew he was blind.

Yitzhak Edri,* 6, would sit and bump his way down the stairs rather than walk. When his mom spoke to him, he tilted his head toward her.

His parents and the community doctors assumed this behavior was an expression of the severe autism that was diagnosed soon after birth.

No one guessed that sometime between birth, when his eyes were checked, and age 6, when all Israeli children undergo eye tests before beginning school, this little boy had lost his sight.

That's because Yitzhak can't speak. Imagine his frustration and terror as his world grew darker and darker.

Though they live in Raanana, in the center of Israel, the family was referred to Hadassah Hospital’s Michaelson Institute for the Rehabilitation of Vision in Jerusalem. The historic institute provides diagnosis, counseling, and support for patients with low vision, enabling them to acclimate successfully and independently in their daily lives.

Dr. Claudia Yahalom, who heads the institute, is an expert both in children with low vision and in children with special needs.

“Children who are born blind have a higher incidence of autism, but here was a child who was born with sight and who, at some unknown time, began to develop cataracts. When I first saw him, both lenses were totally clouded. His world was utterly dark.”

First came the cataract surgery. Then came the moment of truth.

“It was incredible,” says his mother, welling up with tears. “He reached out to grasp a toy. When we spoke he looked at us. We could feel his happiness, and we were overwhelmed with joy.”

“This was one of the most emotional moments of my career,” says Dr. Yahalom, who came to Hadassah Medical Organization in 1995 after graduating from medical school in her native Argentina. “Of course, his autism remains but there's a huge difference in his life experience and his behavior. He’s calmer, walking and seeing properly, and examining the world around him.”

“We have no words to express our thanks to the Creator for all that we have been blessed with and to Dr. Yahalom, who brought light where there was only darkness," says his dad.

*Not his real name