Contact Lenses That Correct Your Vision Overnight

Over the holidays, I fit my son into orthokeratology lenses, commonly referred to as Ortho-K or CRT (Corneal Refractive Therapy) lenses. These are rigid gas permeable contact lenses that are worn only at night while asleep. They reshape the cornea temporarily so that upon awakening, you have normal vision at all distances without the need for glasses or contact lenses! The effect lasts the entire day, even two days for those with lower prescriptions.

This can be life-changing, especially for those who cannot tolerate soft contact lenses due to dryness or irritation or who are active in sports. Ortho-K lenses have been used for decades but are gaining popularity at an incremental rate due to recent studies which show that corneal refractive therapy is one of the most effective methods of slowing down the progression of nearsightedness in children.


Ortho-K lenses can also be used on adults who choose to not undergo surgical procedures like LASIK or PRK to correct vision. Just like for children, the lenses are prescribed for overnight use to temporarily reshape the cornea. Depending on your prescription, the process can take one night to two weeks to achieve its desired effect. Check with your optometrist to determine if you or your child is a good candidate.

My son’s prescription was mild to moderate; he was able to see clearly by the second day. From a personal perspective, here are some tips:

1. The lenses will suction onto the eye overnight so it is very important that the lens is moving freely before removing. Use artificial tears or saline from the bottle to lubricate the eye. After blinking a number of times and some manipulation of the lower lid, the lens will begin moving. He should be able to feel the lens move. Once it moves, he may now remove the lens.
2. It’s always best to remove the lenses using your fingers. However, some people rely on a plunger tool to remove the lens. If you use a plunger, apply the plunger at the 6 o’clock position and not direct center of lens to remove. This will have less of a suction effect, which can be painful if the lens is not moving freely.
3. Once your vision has reached its desired effect, buy a spare pair of lenses from your optometrist. I broke my son’s lens the second week, and since the lenses are custom made, it took one week for the replacement lens to arrive. During this time, his glasses were too strong for him to use, but his current vision was too blurry to see well.
4. You still need ultraviolet protection outdoors so make sure that you or your child use sunglasses outdoors.
5. There is always a risk of infection anytime you sleep in your contact lenses so make sure you always wash your hands before touching your eye or the lenses. Keep your lens case clean, discarding every few months. At the first sign of irritation or abnormal change in vision, contact your optometrist.

My son is extremely happy to be free of glasses and I’m happy to see his eyes again, instead of being hidden behind eyeglasses.

For more information, please visit the following links:

~Cindy P. Wang, OD, FAAO
President, San Gabriel Valley Optometric Society
California Optometric Association

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