AS YOU step inside the subway to head home, you are surrounded by people whose eyes are glued to their phones. When you get home, your siblings are on their tablets, your mom is on her laptop, and your dad is watching the television. While we depend on these devices in our daily lives, they have resulted in nationwide vision problems like xerophthalmia, which dries our eyes, and myopia, better known as short-sightedness. These sight issues have resulted in an increased frequency of vision correction surgeries such as LASIK, LASEK, and intraocular lens implantation (IOL) in Korea. The Yonsei Annals spoke with Seo Kyoung-yul (Prof., College of Medicine) and Jun Ik-hyun (Assistant Prof., College of Medicine) to learn about the prospects for ameliorating this public health crisis, as well as the procedure and effects behind vision surgeries.

A vision epidemic

   Myopia, or near-sightedness, is a visual impairment that has been worsening in Korea within recent decades. According to the National Health and Nutrition Survey conducted from 2008 to 2012, the rate of myopia among Korean teenagers aged 12 to 18 was 80.4%. The screens of electronic devices emit blue light, which can reach our retina, the inner lining of the back of our eyes. Our retinas do not hold the ability to reflect or block blue light, triggering macular [1] degeneration, which causes blurred or reduced central vision. According to the World Health Organization (WHO), out of 2.2 billion in the world that suffer from a sort of vision impairment, 51.6% of people with myopia were from Asia. Furthermore, WHO estimated that approximately 97% of Korean youth suffer from myopia [2]. Children use electronic devices from an increasingly younger age, making them more at risk for contracting visual impairments like myopia. Ophthalmologists recommend that people should wear blue light protection glasses to prevent our light-sensitive cells in the retina from being damaged [3].

How technology worsens eye health

   The dependence on electronic devices to carry out basic, daily activities has inevitably meant that Koreans spend an average of 104 minutes per day on their smartphones [4]. Continuous usage of these devices reduces the amount people blink, leading to eye dryness—medically known as xerophthalmia. According to the Health Insurance Review and Assessment Service, the number of Korean patients suffering from xerophthalmia was over 2 million in 2018. Global eye health products company Bausch + Lomb found that looking at screens can reduce blinking rates by 66%, translating to merely 18 blinks per minute [5]. Blinking is essential for basic eye health as it increases the lubrication needed to add necessary nutrients and minerals, like vitamin A, to the surface of the eyes. If the eyes do not get sufficient lubrication and vitamin A, they are more likely to contract the progressive eye disease xerophthalmia, which causes the lacrimal glands—the organs used to produce tears—to function inadequately [6]. 

   Professor Seo claims that one can self-diagnose by checking for a heavy eyelid sensation and symptoms of “irritation, glare, or fatigue.” At an early stage, xeropthalmia can be treated with artificial tears, ointment, or gel to lubricate the eyes. Intense pulsed light (IPL) can also be used to liquefy and release the hardened oils trapped in the glands [7]. LipiFlow is another popular method that is specifically designed for removing blockages from the glands and produce oils that make up the top protective lipid layer of the tear film [8]. If not treated early upon discovery, xerophthalmia can worsen, leading to conditions ranging from night blindness to damaged corneas. Therefore, periodic eye breaks from looking at electronic devices are also crucial in preventing the contraction of xerophthalmia.

The difference between LASIK and LASEK

   LASIK is a surgical eye procedure that improves vision by correcting the refractive error, which is when our eyes cannot focus on images clearly due to blurred vision. First, a flap is made on the front part of the cornea, which is then lifted. A laser is then used to cut the cornea, thus molding the cornea, and repositioning the corneal incision. LASIK has advantages such as less post-surgery discomfort and improved vision. However, since the corneal section that was cut is merely repositioned and unstable, there is a risk for the section to dislocate, causing blurred vision and the loss of the outermost corneal layer.

   LASEK is very similar to that of LASIK, where refractive errors are corrected through corneal reshaping. LASEK, however, does not make an incision on the front of the cornea but removes only the outer coat of the cornea, and then cuts it using a laser. Post-surgery consequences include severe pain and slow vision recovery. Jun claims that “corneal inflammation is relatively likely” since the surgery removes the outermost corneal layer. However, as there is no direct incision made, there is no complication related to the treated section after the corneal epithelium—a barrier to protect the cornea—regenerates. Jun recommends that "patients who have a relatively thin cornea or take part in dynamic activities, such as sports players, should undergo this surgery.”

Intraocular lens implantation

   There has also been a surge of attention to IOL in Korea since its first operation in 1994, as clinical studies show that patient satisfaction is higher than 99.4% [10]. IOL is a surgery in which an artificial lens is inserted into the eyeball to correct refractive power. Jun claims that two types of lenses can be inserted: one is “fixed to the iris and inserted in the front,” and the other is “inserted in the posterior space between the iris and lens.” During surgery, the cornea is incised, the lens is inserted into the eyeball, and finally, the lens is fixated. The main advantage of IOL is that it can be performed on patients whose myopia is too high or the cornea is too thin, making LASIK and LASEK impossible.

   Jun notes that the downside of the surgery is that the lens can lead to “corneal endothelial cell failure, cataracts, or glaucoma,” which all decrease vision. In addition, there is a possibility of endophthalmitis, an inflammation of the internal eye tissues. However, lens implantation rarely causes side effects, which is reflected by the high demand of patients.

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   The surge in the use of digital devices has caused people to increasingly seek out optical operations such as LASIK, LASEK, and IOL. While vision impairments are on the rise, surgeries offer possible solutions. However, people must not view the availability of these surgeries as an excuse for bad eye care. Make sure to keep up with regular eye exams to prevent the development of these vision disorders in the first place.

[1] Macular: The part of the retina responsible for clear vision in your direct line of sight.

[2] World Health Organization

[3] Medical News Today

[4] Korea Information Society Development Institute

[5] Bausch + Lomb

[6] MedicineNet

[7] Dry Eye Directory

[8] DRY EYE & MGD

[9] Chosun Ilbo

[10] Hankyung Magazine