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, 

www.ovcbrighton.com/ortho-k/faq/#:~:targetText=How%20often%20do%20I%20need,right%20after%20the%20first%20night.

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.

Background:

Daily wear soft contact lenses are the type of eye contact lenses that people typically wear during the day time. These lenses are soft and flexible to the touch and are made of materials such as silicone and hydrogel (Eyeglass World), contributing to the characteristic of the lens molding to the shape of the wearers’ eyes once they are put in. This variation of lenses are more traditional and well-known than ortho-k lenses. From personal experience, my eye contact lens trial assistant gave the analogy of contact lenses being a pair of shoes. It makes sense to wear your shoes when you wake up and go outside during the day, but it would not make sense to wear your shoes. Although it may be common sense to some that daily wear soft contact lenses may be the answer, let’s hold off on making fast assumptions and discuss the advantages and disadvantages of this variation. 

Advantages:

General advantages to wearing daily wear soft contact lenses include not worrying about needing to get a certain amount of sleep to be able to see well the following day. Ortho-k lenses require the wearer to sleep a certain number of hours for them to see, approximately six to eight hours (Optimum Vision Care). If the wearer does not sleep the instructed number, the person will have fuzzy or blurry vision and will not be able to see as clearly as they would have if they wore the contacts longer. However, with soft contact lenses, the wearer can put them in whenever they wake up, no matter the amount of sleep they got, and switch to glasses freely during the day. 

To give more scientific evidence to the advantages of wearing daily contacts, one study was performed to see and assess the visual acuity, perceptions of vision that affects quality of life, and symptoms of wearing daily wear soft contact lenses (SCL) and overnight corneal reshaping (OCR). From performing the randomized crossover clinical trial, subjects noted that SCL gave better visual acuity (vision sharpness measured from the ability to see letters or numbers from a distance) and less trouble with glare than OCR lenses (Lipson, Sugar, Musch). While some may not trust this experiment that much due to having only a pool of 81 enrolled patients, it is not low to the point where it is suspicious, and the experimenters do a good job of having their subjects be randomized. 

In another experiment, the scientists conducted the study in order to examine the various impacts of wearing the two types of contact lenses that it had on eyes and their alignment, nearsightedness, or other issues affecting the eyes (Gifford, Gifford, Hendicott, Schmid). This study included subjects that were approximately the age of 25.8 plus or minus 3.2 years in age, which includes those in the young adult age and most likely some of the readers. By keeping this study’s credibility and relatability in mind, hopefully it will have an impact on readers’ assessment of these two contact lenses’ effectiveness and quality. One conclusion the scientists made that revealed an advantage of SCL contacts was that it led to less exophoria, or the tendency for eyes to drift away from each other (Healthline).

Besides the clear health benefits in wearing soft contacts, it gives people more assurance in choosing soft contacts over ortho-k lenses because soft contacts are more popular and traditional. Therefore, people will feel they are safer to use than ortho-k lenses, since there are fewer severe incidents that occurred. For example, in Hong Kong, the researchers sent out surveys to Hong Kong optometrists to assess what kinds of contact lenses their patients wear. The purpose was to see what percentage of people wear a certain type contact lenses between the period of 2007 to 2008. Once the results were taken a look at and analyzed, it revealed that most residents use soft contacts over other types of contact lenses (Charm, Cheung, Cho). Although the Hong Kong population may not be similar to the readers’ demographics, Hong Kong is a densely populated region, an example of a large pool of people in the world, and are technologically advanced. 

Disadvantages:

In comparison to ortho-k lenses, soft contacts are worn during the day, which means the wearer will not be contact-free like ortho-k wearers are. Further disadvantages of soft contact lenses are equivalent to the advantages of ortho-k lenses, since the soft contacts do not have the same health benefits. These disadvantages of soft contacts and advantages of ortho-k lenses can be read in the other blog post on ortho-k lenses.

Works Cited:

Chang, Julia. “Orthokeratology – FAQ.” Optimum Vision Care, 2012, 

www.ovcbrighton.com/ortho-k/faq/#:~:targetText=How%20often%20do%20I%20need,right%20after%20the%20first%20night.

Charm, Jessie, et al. “Practitioners’ Analysis of Contact Lens Practice in Hong Kong.” Contact 

Lens and Anterior Eye, vol. 33, no. 3, June 2010, pp. 104–111., doi:10.1016/j.clae.2010.02.001.

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.

“Learn About Contact Lenses: What Are Contacts Made of?” Eye Glass World, 

www.eyeglassworld.com/eye-vision-patient-education/contact-lenses/what-are-contacts-made-of#:~:targetText=Most%20extended%20wear%20contact%20lenses,contact%20lens%20into%20the%20eye.

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.

Wells, Diana. “Exophoria.” Edited by Debra Sullivan, Healthline, 2018, 

www.healthline.com/health/exophoria#exophoria-vs-exotropia.\

In this blog, I will be exploring the two variations of eye contact lenses: soft disposable daily wear contact lenses and orthokeratology contact lenses, also known as ortho-k lenses. There is a large debate on which type of contact lenses is better, with the daily contact lens wearers claiming that it does not affect the amount of sleep they need and the ortho-k lens wearers boasting that their vision slowly improves during gradual usage. With this website, hopefully those who need contact lenses and do not know much about either variation can figure out which one will be best suited for their needs. This blog can also simply teach readers interested in the topic more about eye contact lenses, even if they do not need them. It is important to keep in mind that one type of contact lenses may be the best for you, but not for another person. 

The following blog posts will explore both types of contact lenses, explaining the general background, advantages, and disadvantages of wearing them.