ABC30 ORIGINAL: These new contact lenses can be worn by kids while they sleep

FRESNO, Calif. (KFSN) -- Casey doesn't start her day putting in her contacts. It's how she ends it.

The 11-year-old Sanger 5th grader wears special lenses at night while she's sleeping and by morning, she has clear vision.

"We're pretty excited about the opportunity because of what it can do for the child," says Dr. Michael Harmon, an optometrist at Fogg, Maxwell, Lanier & Remington EyeCare in northeast Fresno.

Harmon recommends the treatment to patients who are candidates for CRT or corneal refractive therapy lenses.

The lenses have been prescribed since 2003 to eliminate the need for contacts or glasses during the day.

But now, they're being used to help slow the progression of myopia or near-sightedness in children, which is increasing at a staggering rate.

Severe myopia can be associated with a number of other chronic eye problems.

"Looking at near-sightedness as a disease now because of co-morbidities, we call them, glaucoma, cataracts and myopic macular degeneration, that's the reason for the attention on slowing," Harmon says.

The rigid contact applies gentle pressure to temporarily reshape the cornea while the patient is sleeping, correcting vision for the following day.

The cornea's shape returns so the correction again is temporary.

But over time, it reduces the severity of nearsightedness.

It's freedom, especially for active kids like Casey, who plays softball and shows horses without needing glasses or contacts.

"I've told my friends what I wear because I stopped wearing my glasses and they're like, 'Hey! Why did you stop wearing your glasses?'" Casey says.

Casey's set of CRT lenses includes one blue one for the right eye and a red one for the left eye, so she can easily tell them apart when she puts them in each eye.

At first, it took some tears.

"When you first get them, your eyes aren't used to them so you feel like you have a big rock in your eyes. So your eyes will water and stuff but once you go to sleep, you don't feel them anymore."

It took about a week for Casey to become comfortable with wearing and caring for the lenses which made a literal day and night difference at school.

"It was kind of hard for me to see the front of the board, what he's written on the board. It's kind of like a blur of letters and words but now with the CRTs, I can just see it clearly," Casey says.

CRT lenses cost about $1600 for one set and a spare set and are not covered by insurance.

Harmon says many families opt for the lenses because of the double benefit of corrected vision during the day, while slowing the progression of their child's nearsightedness.

Since kids' eyes grow along with the rest of them, patients like Casey need to be fitted with new CRT lenses as their eye size and shape changes until adulthood. Once they reach 16 or 18 and stop growing, they can opt for Lasik surgery to permanently correct their vision.

Until then, Casey wears her special lenses every night that help her vision with her eyes wide shut.

Health experts say by 2050, half of the U.S. population will be near-sighted.

Harmon says it's important to slow the progression of myopia, especially for children - to counter our technology-based lifestyle.

Vision can be affected by genetics, the environment, looking at screens throughout the day and not spending enough time outdoors.