(VOVWORLD) - As screen time increases and vision problems become more common at every age, many still misunderstand conditions like myopia, hyperopia, and astigmatism. In this episode of Doctor at Home, we welcome Dr. Dinh Thi Hoang Anh, Head of Ophthalmology at Hong Ngoc Hospital. A specialist in refractive, cataract, and corneal surgery, Dr. Hoang Anh has advanced training in corneal treatment and vision correction and has received multiple national and international ophthalmology awards. She will debunk misconceptions and shares practical advice on protecting vision, using glasses correctly, and when refractive surgery may be considered.
Reporter: Hello Doctor. Many of us often confuse myopia, hyperopia, and astigmatism. Could you explain, in simple terms, what each of these conditions is and how they differ?
Hoang Anh: Myopia, astigmatism and hyperopia are the most common refractive errors that cause reduced vision.Myopia is a condition in which the eyes can see nearby objects clearly, but objects become blurry and unclear when viewed from a distance. The farther the object is, the harder it is to see clearly. Astigmatism causes image to appear blurry or distorted, regardless of whether the object is near or far. In some cases, the image may appear doubled or even tripled. Hyperopia is a condition in which distant vision is clear, but near vision becomes blurry, often accompanied by eye strain, headaches or dizziness after a period of focusing on close-up tasks.
Reporter: What symptoms should people pay attention to if they suspect they might have one of these refractive errors?
Hoang Anh: All refractive errors lead to reduced vision. The main symptom is unclear vision of distant objects, near objects or both.People with refractive errors often squint for long periods or experience eye fatigue when looking at something for too long. In children, frequent frowning or squinting when reading, blinking often or rubbing their eyes repeatedly are common signs of refractive errors. Children may not realize how their vision is being affected, so parents need to pay close attention to their everyday gestures and behaviors to detect problems early and help prevent complications.
Reporter: What are common misconceptions about nearsightedness, farsightedness, or astigmatism that you often encounter in your practice?
Hoang Anh: Myopia cannot heal on its own, as many people mistakenly believe. Instead, it requires correction through various methods.People with myopia can choose to use eyeglasses, contact lenses or consider surgical procedures to correct the refractive error, helping the eyes return to their original visual acuity.
Reporter: When is it necessary to wear glasses full-time, and when is it acceptable to use them only for certain activities, like reading or driving?
Hoang Anh: In reality, your eyes will always try to function at their best, regardless of whether you wear glasses regularly or not. Myopia will not improve or diminish if you try to practice going without glasses for any personal reasons. So, from 0.25 to 0.5 diopters, this is a minor degree of myopia. Distant vision is slightly blurry but does not significantly affect daily life.So, you may not need to wear glasses. If you have from minus 0.75 to 1 diopters, you should start wearing glasses to avoid affecting daily tasks such as driving, sewing, etc. But they do not need to be used constantly.From minus 1.5 to 2 diopters, glasses should be worn regularly to avoid affecting daily work and life. Above 3 diopters, this is a cause of moderate myopia. Not using glasses will cause the eyes to constantly accommodate to see clearly, leading to a rapid increase in the degree of myopia and, more dangerously, retinal degeneration.
Reporter: We frequently hear that children’s eyesight can get worse because of too much screen time. Is that really the case, and what practical habits can families adopt?
Hoang Anh: The eyes of children, especially those under 10 years old, have not yet fully developed. The ciliary muscles and the retina are still sensitive.So, frequent and prolonged exposure to the blue light emitted from phones can cause severe damage. Parents should limit device usage time according to the child's age. For example, in the age group from 6 to 12, when children begin to use electronic devices for learning, usage should only be 1 to 2 hours per day.
Reporter: Astigmatism sounds serious to many people. How harmful is it actually, and can it fully disappear over time?
Hoang Anh: Astigmatism is a refractive error of the eye that occurs when the cornea or the lens has an abnormal shape. Although it is not dangerous, astigmatism causes many discomforts for those affected, such as blurry vision, headaches, eye strain and difficulty seeing at night.Astigmatism cannot heal on its own and generally tends to increase in degree over time. It requires treatment through medical methods.
Reporter: At what point should someone consider refractive surgery, such as LASIK or SMILE? Are there specific criteria that patients need to meet?
Hoang Anh: For people with refractive errors, having surgery is a personal decision.If you find wearing glasses inconvenient and want all daily activities to be more comfortable without having to rely on glasses, then you can opt for surgery. The basic conditions that a patient must meet to be safely and effectively indicated for refractive surgery are being 18 years of age or older and having a stable refractive error for at least 6 months. The cornea must be thick enough so that the remaining corneal tissue after the laser procedure is still safe, minimizing the risk of complications like corneal ectasia. Furthermore, the eyes must be completely healthy, without acute conditions such as conjunctivitis, keratitis, blepharitis, or other infections. Pregnant or breastfeeding women should also not undergo refractive surgery because hormonal changes can alter the eye's refractive error, affecting the accuracy of the surgery.
Reporter: If a person has recently been diagnosed with a refractive error, what are the first steps they should take to manage it properly?
Hoang Anh: After the vision examination process, the patient will be given a prescription for corrective lenses with parameters that match the refractive error in their eyes. The patient can choose to wear eyeglasses, soft contact lenses, or rigid gas permeable overnight contact lenses (Ortho-K). If choosing to wear corrective lenses, patients are recommended to wear the glasses with the correct prescription continuously to limit the progression of myopia and avoid the risk of amblyopia.
Reporter: Before we wrap up, do you have any additional advice for our listeners on how to take care of their eyes and protect their vision?
Hoang Anh: Although refractive errors are not overly dangerous, they cause many inconveniences in daily life and activities. It is advisable to have an eye exam every 6 months, especially for those who already have refractive errors. Do not wait until serious symptoms appear before seeking a doctor. Furthermore, it is necessary to establish healthy lifestyle and living habits. Improve your study and work environment with sufficient lighting, and adjust the distance to about 50-60 cm when reading or using electronic devices. You can apply the 20-20-20 rule to allow your eyes to rest after a period of work or study. Specifically, after 20 minutes of working with electronic devices, you should let your eyes rest for 20 seconds and look at something 20 feet (6 meters) away.
Reporter: Thank you so much, Dr. Hoang Anh, for sharing insights with our listeners today. Eye health is something many of us tend to overlook, and your guidance truly helps us understand how to take better care of our vision.
Hoang Anh: Thank you to our listeners for tuning in to the program.
Reporter: We’ll be back soon with more useful health topics. Until then, take good care and see you next time!