Background:
Orthokeratology contact lenses (ortho-k lenses) are the contact lenses that people wear to sleep, adjusting people’s vision to be close to 20/20 vision when they wake up in the morning and take them out. The result of almost “perfect” vision comes from the lenses shaping the eyes overnight, adjusting for myopia, or nearsightedness, and astigmatism, or blurred vision from irregularly shaped corneas. For the lenses to have its full effect, the wearers need to sleep between six to eight hours, as mentioned in the “Daily wear soft contact lenses” blog post (Optimum Vision Care). A benefit from wearing these lenses are that they prevent the wearer’s vision from worsening, stabilizing his/her vision from continuing to decline. This is a reason why parents allow their children to be prescribed ortho-k lenses, since they aid in the process of preventing worsening myopia (Heiting). Another difference between ortho-k lenses and soft contacts is that ortho-k lenses are hard contacts, meaning the lenses are hard to the touch and are made of firm, but breathable plastic.
Advantages:
The well-known advantages that attract people to choose ortho-k lenses over other variations of contact lenses are how they stabilize the wearer’s vision as time passes and allows them to be contacts-free during the day. The first benefit explains why specialists may recommend ortho-k lenses to children, since they can slow the fast worsening of their vision, or childhood myopia, at a young age (Heiting).
More specific and scientific pieces of evidence that prove to benefit ortho-k wearers include less activity limitations, less issues with symptoms concerning the eyes, and less dependence on refractive correction in comparison to soft contacts, according to a study (Lipson, Sugar, Musch). This study mandated that their participants experience wearing both soft contacts and ortho-k lenses, with a wash-out period in between, to compare and contrast the benefits of each clearly. In another experiment, the scientists reached the conclusion that ortho-k lenses included lower accommodative lag and could prove to benefit those with binocular vision disorders (Gifford, Gifford, Hendicott, Schmid). Even though the scientists found these results, it would be more reassuring if the trial duration was longer than 18 months to lower the chance of incorrect results. In addition, another article written by a special interest group, All About Vision, reports on how these contact lenses gives wearers the flexibility to still get LASIK eye surgery (Heiting). For those who do not know, LASIK eye surgery is a popular laser refractive surgery procedure performed to fix vision problems (Mayo Clinic). Dr. Heiting also informs his audience to keep in mind that ortho-k lenses are a good fit for some, depending on age, career, eye myopia, and other factors as well as reassuring that they are safe as long as they are breathable, gas permeable (GP) lenses approved by the Food & Drug Administration (FDA). Although this article from All About Vision may not be a scientific journal publication including an experiment, it still successfully highlights general, useful information about ortho-k lenses, similar to a review article.
In another journal article, the authors report that their test subjects preferred Corneal Refractive Therapy (CRT) contact lenses over the soft ones and that the vision of the subjects when they were wearing CRT lenses was 20/20 while the subjects’ vision when wearing soft contacts were 20/25. Therefore, CRT lenses resulted in better vision when used over soft lenses (Lipson, Sugar, Musch). This study also included having their subjects wear both types of contact lenses in between a break period. The purpose of this procedure is to reduce the probability of biases affecting their choice of which contact type they preferred, since they were asked to pick a preferred one at the end of the experiment.
Disadvantages:
Although ortho-k lenses may come with many cool benefits, they come with a price of risking severe consequences. For example, in a health article by NPR, the author warns her readers of the dangers of using these contact lenses with a real life example of a child needing a cornea transplant after getting a fungal infection. The infection was so severe that it almost perforated his cornea and permanently destroyed his eyesight (Ostrov). However, she does note that the probability of experiencing a repercussion similar to the one mentioned would be lowered if the wearer was careful and clean with their hygiene and eye care. Even though this article is also not a part of a scientific journal, it includes a real life example of someone who was negatively impacted from wearing ortho-k lenses. It could give awareness to the audience on whether they would be willing to wear ortho-k lenses despite the possible repercussions that come with the choice.
Works Cited:
Chang, Julia. “Orthokeratology – FAQ.” Optimum Vision Care, 2012,
Gifford, Kate, et al. “Near Binocular Visual Function in Young Adult Orthokeratology versus
Soft Contact Lens Wearers.” Contact Lens and Anterior Eye, vol. 40, no. 3, 2017, pp. 184–189., doi:10.1016/j.clae.2017.01.003.
Hataye, Alaina Softing. “LASIK Eye Surgery.” Edited by Sandhya Pruthi, Mayo Clinic, Mayo
Foundation for Medical Education and Research, 8 Nov. 2019, http://www.mayoclinic.org/tests-procedures/lasik-eye-surgery/about/pac-20384774.
Heiting, Gary. “Ortho-K And Corneal Refractive Therapy: Overnight Contacts To Correct
Myopia.” All About Vision, Sept. 2016, http://www.allaboutvision.com/contacts/orthok.htm.
Lipson, Michael J., et al. “Overnight Corneal Reshaping versus Soft Disposable Contact Lenses:
Vision-Related Quality-of-Life Differences From a Randomized Clinical Trial.” Optometry and Vision Science, vol. 82, no. 10, Oct. 2005, pp. 886–891., doi:10.1097/01.opx.0000180818.40127.dc.
Ostrov, Barbara Feder. “Overnight Contacts Can Help Kids’ Sight During Day, But Also Carry
Risks.” NPR, NPR, 21 May 2015, http://www.npr.org/sections/health-shots/2015/05/21/406502395/overnight-contacts-can-help-kids-sight-during-day-but-also-carry-risks.
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