Refractive errors include nearsightedness (myopia), farsightedness (hyperopia), and astigmatism; they are considered disorders of light refraction in the eye rather than diseases of the eye.
- Nearsightedness (Myopia): Blurry vision when looking at distant objects.
- Farsightedness (Hyperopia): Blurry vision when looking at nearby objects.
- Astigmatism: Distorted vision due to an irregularly shaped cornea.
1. Causes:
- Prolonged near-vision tasks under artificial light.
- Frequent use of modern technological devices such as computers, TVs, and phones, causing continuous eye strain.
- Studying and working in poorly lit environments or with excessive blue light.
- Nutritional deficiencies, particularly lack of Vitamin A.
- Genetic factors.
- Elongated eyeball structure.
2. Symptoms:
- Difficulty reading small text on a board.
- Squinting when looking at distant objects.
- Holding books very close to the eyes while reading.
- Clear vision up close but blurry vision at a distance.
- Eye strain and discomfort after prolonged reading.
- Possible headaches and eye pain.
3. Prevention:
- Balance near-vision tasks under artificial light with outdoor activities. Every 45-60 minutes of close work, such as studying or watching TV, children should take a break and look at something far away for about 10-15 minutes.
- Maintain a reasonable distance between the eyes and reading materials, with books, notebooks, and devices positioned at least 30 cm from the eyes.
- Use yellow lighting and make the most of natural light.
4. Treatment:
- Follow the doctor's instructions, especially when wearing glasses suited to the eye condition. Even a minor refractive error of 1-2 diopters can significantly impair vision if not corrected with glasses. Regular eye check-ups every six months are recommended.
- Nearsightedness: Wear diverging lenses.
- Farsightedness: Wear converging lenses.
- Astigmatism: Wear cylindrical lenses.
- Or LASIK Surgery: Uses laser to permanently alter the shape of the cornea, improving vision significantly. LASIK has many advantages, such as being painless, with vision recovery typically occurring the day after surgery, and a wide treatment range. However, like all surgeries, LASIK carries some risk, though the incidence is very low, averaging only 0.4-1%.