Carlene Knight, 54, is one of the first patients in a landmark study designed to try to restore vision in those who have a rare genetic disease that causes blindness.

Carlene Knight, 54, is one of the first patients in a landmark study designed to try to restore vision in those who have a rare genetic disease that causes blindness.

Kalberer and Knight are two of the first patients treated in a landmark study designed to try to restore vision to patients like them, who suffer from a rare genetic disease.

But in those experiments, doctors take cells out of the body, edit them in the lab and then infuse the genetically edited cells back into patients.

The experiment Knight and Kalberer volunteered for marks the first time scientists are using CRISPR to edit DNA when it's still inside patients' bodies.

By the end of the year, the researchers say they expect to share the first data on whether the procedure restored any vision for the patients.

Knight and Kalberer were born with a form of Leber congenital amaurosis, which destroys light-sensing cells in the retina, devastating vision.

A defect in a gene called CEP290 causes the version of the disease Knight and Kalberer were born with.

"I have no peripheral vision whatsoever," says Knight.

Michael Kalberer, 43, was born with a form of Leber congenital amaurosis, which destroys light-sensing cells in the retina.

He's hopeful that the procedure will help restore his vision.

Michael Kalberer, 43, was born with a form of Leber congenital amaurosis, which destroys light-sensing cells in the retina.

He's hopeful that the procedure will help restore his vision.

I do not have visual autonomy," Kalberer said during the first of two interviews, which occurred in September just before undergoing the procedure.

That should trigger production of a protein that could restore the function of the light-sensing cells in their retinas, preventing any further loss of vision and possibly restoring at least some of their lost vision.

Doctors are comparing the vision of patients before and after the procedure, and between their treated and untreated eyes, to see if the procedure is helping them see better.

Doctors are comparing the vision of patients before and after the procedure, and between their treated and untreated eyes, to see if the procedure is helping them see better

Doctors are comparing the patients' vision before and after the procedure, and between their treated and untreated eyes to see if the procedure is helping them see better