ABC News' Chris Connelly, Jesus Ayala and Jennifer Pereira report:
As a member of the Grammy Award-winning group the Black Eyed Peas, apl.de.ap has rocked a million faces, but he hasn't seen them all.
The 37-year-old Filipino-American rapper, drummer and record producer was born with a condition known as nystagmus, which is characterized by an involuntary movement of the eyes that limits vision.
In apl.de.ap's case, the nystagmus causes his eyeballs to vibrate. The vibration combined with his nearsightedness makes the singer, whose birth name is Allan Pineda Lindo Jr., legally blind.
When he performs in front of thousands of cheering fans, all apl.de.ap can see is the first five rows of fans and only the shapes of his bandmates Taboo, Fergie and will.i.am.
"I can't see the facial detail," he told ABC News. "I go by the sound of your voice or somehow I get some tentacles that I can feel when someone is there."
"I do measurements in my head," he explained of how he pulls off the band's complicated dance moves and stage performances. "When I picture the stage, I already have the picture in the middle so when I'm break dancing I just picture that square in my head. And I just go for it."
After spending his entire life working within the limitations of his disability, apl.de.ap decided to undergo an operation that would implant an artificial lens into each of his eyes to correct both his nearsightedness and his nystagmus.
The singer turned to Dr. Brian Boxer Wachler of the Boxer Wachler Vision Institute in Beverly Hills, Calif., to complete the procedure.
"This is going to be one of the most challenging surgeries I've ever done because I am working with a moving target," Dr. Boxer Wachler told ABC News just prior to the surgery on July 10. "I have to do very delicate maneuvers in order to make the entry point and position the lens inside the eye."
During the 40-minute procedure, Dr. Boxer Wachler inserted a new lens into each of apl.de.ap's eyes, all while the singer lay awake.
After the surgery was over, the singer emerged from the operating room with a far clearer vision of his joyful mother. Prior to the surgery he'd said the ability to see his mom more than 10 feet away would be, "the happiest time and day of my life."
"The fuzziness has already gone away," he said as he hugged his mom. "Wow, it's like I have my contacts."
One week later apl.de.ap was back in the recording studio and reporting even greater progress from the surgery.
"I can see a lot more details in faces," he said. "I can actually see people from a distance now. I can see almost 100 feet away, before I couldn't see that."
Apl.de.ap's eyesight will only continue to improve as he adjusts to the lenses inside his eyes, according to Boxer Wachler. For the patient, that newly bright future makes the surgery well worth the effort.
"It wasn't as scary as I thought," apl.de.ap said. "I just felt a little pressure on my eyes. It was easy, simple. It's definitely a great success."