Rafael Romo
Reporting

(CBS) CHICAGO Derrek Lee spoke out Friday thanking everyone for their support and asking for prayers on behalf of his three-year-old daughter who has lost vision in one eye.

The Cubs batting champion talked about his daughter's diagnosis of Leber's Congenital Amaurosis.

CBS 2's Rafael Romo talked to another family coping with the same disease.

It's difficult to imagine the challenge Jack faces when you see him playing on the court.

He can only hear the bells inside the ball he's playing with. He can't see anything at all.

"Jack was diagnosed as having a visual impariment at about three months of age, but we didn;t actually get the diagnosis of Leber's until he was six -months-old," said Jack's mother Beth Falejczyk.

Jack's disease made the headlines recently after the three-year-old daughter of Cubs first baseman Derrick Lee was diagnosed with the same condition.

"We just ask for everyone's prayers," said the Cubs first baseman."You know, we need a miracle; we need your prayers."

The 2005 batting champion returned Friday to Wrigley Field after a short leave of absence to care for his daughter.

"We've been fortunate that Jada, she still has great vision in one eye as of right now," he said.

"When we think of Leber's Congenital Amaurosis we think of basically, a blinding disease," said UIC ophthalmologist Dr. Kimberlee Curnyn.

Curnyn, who treats children with Leber's, says the disease is unforgiving.

"Unfortunately, it's usually the children who lose sight in both eyes," she said. "It's a degenerative disease and most children really have very little if any sight to go by."

Derrek Lee has gone one step further -- he's started his own foundation called "Project 3000." His goal is to help kids with the disease get the genetic testing they need.