Myopia (nearsightedness)
Why Types Symptoms Causes Risks Treatment Self help discussion Vision therapy
Nearsightedness (myopia) is the ability to see clearly at a near distance, but far objects are less clear. The conventional belief is that myopia occurs secondary to an excessive curvature of the cornea and/or a longer-than-normal eyeball. The degree of nearsightedness can vary widely, as can the age of onset and the rate of progression. Most myopia develops during the school years and stabilizes in the teenage years.
The widespread use of computers has made the problem worse. In the 1980s, before the present computer-driven world, only 2% of Dutch army recruits from a farming background were myopic, but 32% of those with an advanced education were nearsighted. Presently, in some urban parts of Asia, the percentage is nearing 90%. Half of the world’s population will be myopic by 2050 if current trends continue.
How the Eye Focuses
The cornea actually has the most focusing power of the eye. But its curve, and therefore its focusing ability, is fixed. The flexible lens fine-tunes curvature to aim incoming light on the retina. Fine muscles in the ciliary body cause the lens to flatten or bulge in order to focus on an object.
In cases of nearsightedness (myopia), the eyeball is too long, the incoming light undershoots the mark and the light is focused just before the retina, rather than right on it. The result is vision blurriness.
Types of Myopia
Simple. This is the most common type is where the eyeball is naturally more oval than round. This is most often related to genetics, but it can be affected by environmental factors as well. This is the easiest form to improve, for example, through eye exercises.
Induced or acquired. This can be caused by certain medications and/or cataracts, which can change the way light is refracted to the retina.
Nocturnal. During the day your distance vision is fine, but at night with low light, seeing distance objects, without glasses, is more difficult.
Degenerative. Called pathological myopia, this is where the length and shape of your eye condition increases over time, ultimately increasing the risk of retinal damage. This condition is also known as myopic macular degeneration.
Myopia Symptoms
Blurred sight at a distance is the primary symptom of myopia, with the ability to see close-up detail more clearly. Both eyes are usually involved, but one may be worse than the other. Sight tends to be worse at night.
The early signs of myopia tend to occur in the child who has his or her face in a book or electronic device for long periods of time, without ever looking up. That child might experience some blurring of objects in the distance as s/he looks up. School vision screening now catches many of these cases, but not all. Sometimes the discovery may be as simple as a child in the outfield that is unable to catch fly balls but is able to do so after s/he gets prescription glasses.
Causes
The available studies should make it hard for any logical mind to think that nearsightedness can be due to genetics only. After it was recognized that highly educated people are more likely to be myopic, conflicting opinions arose as to whether myopia is genetically caused and/or environmentally caused. Genetics influence how the eye grows, but what causes normal vision (emmetropic) or myopic vision is heavily influenced by other factors.1
Hereditary. Certain chromosomes are linked to myopia, nonetheless the genetic effect is larger in people with a higher level of education.2 Myopic children are likely to have myopic parents.3 Myopia experienced as a child, in people with myopic parents, and in those who get little outdoor exercise, increases the risk of myopia in adults, especially women.4
Education and occupation. Myopia develops during the school years, especially in college students; it is much lower in uneducated or poorly educated people.5 Occupations that require much close work are more likely to increase the risk of myopia.6
Diet. The increase of myopia in undeveloped countries has paralleled the increase of a Western-type diet with a heavy reliance upon sugar and processed ingredients. It has been theorized that this change induces myopia.7
Diabetes. Myopia in diabetics appears to be associated with metabolism.8 A study investigated whether the increasing rate of nearsightedness in diabetics was due to changes in the lens or the length of the eyeball (axial length). The researchers concluded that the changes were due to lens changes, not axial length changes.9
Lack of exercise. Physical exercise has a protective effect with respect to nearsightedness.10 Outdoor physical exercise is especially protective.11 Researchers have learned that increased stimulation by outdoor light, results in increased dopamine release, which is known to reduce axial elongation.12
Premature birth. Children born prematurely are more likely to be nearsighted. 13
Psychological stress. It is theorized that some children may become nearsighted due to environmental stress factors, such as difficult family situations. Being nearsighted enables them to not "see" or block out, to some extent, what is going on in their family life or environment that is unpleasant.
Oxidative stress. Researchers have found that oxidative stress14 may alter regulatory mechanisms of eye diseases, which have been linked to myopia, also retinal detachment, glaucoma, cataracts, and macular neovascularization.
High intraocular pressure has been found to be a cause of axial lengthening and consequently, myopia.15
Kawasaki disease, which is a condition involving inflammation of arteries, lymph nodes, and mucous membranes, creates a substantially higher risk for developing myopia.16
Trace minerals. Of trace minerals measured in hair samples in Chinese college students, copper levels increased with the degree of myopia, while zinc, lead, aluminum, iron, and potassium decreased with the myopic degree.17
At Risk for Other Conditions
Patients with myopia, especially if severely nearsighted, are at higher risk for many conditions:
- Myopic macular degeneration results in the stretching of the retina and potential vision loss.
- Retinal hemorrhage. A study linked the occurrence of lacquer cracks (breaks in the Bruch's membrane) in patients with high levels of myopia and low macular pigment density. These are early warnings of retinal hemorrhage.
- Psychological. Being nearsighted often causes a feeling of isolation, especially in adolescents.
- Macular holes, especially in women
- Lattice degeneration
- Glaucoma, especially in people who are heavy computer users
- Eye floaters
- Computer eyestrain
Conventional Treatment
Glasses or contacts are prescribed for correction of the refraction error.
LASIK surgery is another option for some people.
Low-dose atropine (for about two years) is sometimes prescribed for children; its use is controversial since there can sometimes be side effects, and 10% of children do not respond to the treatment.18,19
Other. Pirenzepine drops, cyclopentolate drops, orthokeratology, and special contact lenses are moderately effective.20
Self Help
Vision is not static and changes over time. Even without any pathology, vision tends to weaken as we age. As eye muscles become weaker, the eye lens becomes less flexible. Compounding these changes, our ability to break down nutrients and deliver them to our eyes becomes compromised. We can help maintain healthy vision through diet, regular exercise, and targeted supplementation. These approaches can also reduce the risk of future eye disease.
- Supplement with nutrients that support healthy vision. Research has linked macular pigment density with axial length; consequently carotenoids such as lutein and zeaxanthin which support macular pigment may be helpful.21,22,23 Bilberry may also be helpful and there is contradictory research as to whether vitamin D3 is helpful.
- Diet and lifestyle protocol - see our recommendations for diet / lifestyle.
- Natural daylight. Some research suggests that natural light exposure may counter-balance too much indoor/close up work causing strain on the eyes. Even on an overcast day, exposure to natural light for 2-3 hours may be helpful.
- Manage chronic stress. Long-term tension has been shown in research to contribute to serious disease and is suspected as a causative factor in eye conditions.
- Eat healthy. Research has verified that a healthy diet that includes daily intake leafy, green vegetables and whole grains can significantly lower the likelihood of developing eye disease.
- Exercise. Develop a regular exercise routine. A minimum of 20-30 minutes of vigorous walking or swimming a week for example is excellent for eye and overall health.
- Computer Users. If you are a computer user, please review our section on computer fatigue syndrome.
- Vision therapy may be helpful.
Nearsightedness News
Want to learn more? See our blog news on myopia.
Research and Footnotes
See the research on natural options for treating myopia.
1. Goldschmidt, E., Jacobsen, N. (2014). Genetic and environmental effects on myopia development and progression. Eye (Lond), Feb;28(2):126-33.
2. Ibid. Goldschmidt. (2014).
3.Morgan, I., Rose, K. (2005). How genetic is school myopia? Prog Retin Eye Res, Jan; 24(1):1-38.
4. Parssinen, O., Kauppinen, M., Viljanen, A. (2014). The progression of myopia from its onset at age 8-12 to adulthood and the influence of heredity and external factors on myopic progression. A 23-year follow-up study. Acta Ophthalmol, Dec;92(8):730-9.
5. Maul, E., Barroso, S., Munoz, S.R., Sperduto, R.D., Ellwein, L.B. (2000). Refractive Error Study in Children: results from La Florida, Chile. Am J Ophthalmol, 129:445–454. Also three other similar studies: (Pokharel, 2000; Zhao, 2000; He, 2004).
6. Ibid. Goldschmidt. (2014).
7. Cordain, L., Eaton, S.B., Brand, J., Lindeberg, S., Jensen, C. (2002). An evolutionary analysis of the aetiology and pathogenesis of juvenile-onset myopia. Acta Ophthalmol Scand. Apr, 80(2):125-35.
8. Jacobsen, N., Jensen, H., Lund-Andersen, H., Goldschmidt, E. (2008). Is poor glycaemic control in diabetic patients a risk factor of myopia? Acta Ophthalmol, Aug;86(5):510-4.
9. Fledelius, H.C., Miyamoto, K. (1987). Diabetic myopia--is it lens-induced? An oculometric study comprising ultrasound measurements. Acta Ophthalmol (Copenh), Aug;65(4):469-73.
10. Jacobsen, N., Jensen, H., Goldschmidt, E. (2008). Does the level of physical activity in university students influence development and progression of myopia? --a 2-year prospective cohort study. Invest Ophthalmol Vis Sci, Apr; 49(4):1322-7.
11. Rose, K.A., Morgan, I.G., Ip, J., Kifley, A., Huynh, S., et al. (2008). Outdoor activity reduces the prevalence of myopia in children. Ophthalmology, Aug; 115(8):1279-85.
12. French, A.N., Ashby, R.S., Morgan, I.G., Rose, K.A. (2013). Time outdoors and the prevention of myopia. Exp Eye Res, Sep; 114():58-68.
13. Fledeliu, S. H. (1976). Prematurity and the eye. Ophthalmic 10-year follow-up of children of low and normal birth weight. Acta Ophthalmol Suppl, 128():3-245.
14. Francisco, B.M., Salvador, M., Amparo, N. (2015). Oxidative Stress in Myopia. Oxid Med Cell Longev, 2015:750637.
15. Genest, R., Chandrashekar, N., Irving, E. (2012). The effect of intraocular pressure on chick eye geometry and its application to myopia. Acta Bioeng Biomech, 2012:14(2):3-8.
16. Kung, Y.J., Wei, C.C., Chen, L.A., Chen, J.Y., Chang, C.Y., et al. (2017). Kawasaki Disease Increases the Incidence of Myopia, Biomed Res Int, 2017:2657913.
17. Cai, Y. (2011). Determination of select trace elements in hair of college students in Jinzhou, China. Bio Trace Elem Res, Dec;144(1-3):469-74.
18. Schittkowski, M.P., Sturm, V. (2018). Atropine for the Prevention of Progression in Myopia - Data, Side Effects, Practical Guidelines. Klin Monbl Augenheilkd, Apr;235(4):385-391.
19. Tran, H.D.M., Tran, Y.HY., Tran, T.D., Jong, M., Coroneo, M., et al. (2018). A Review of Myopia Control with Atropine. J Ocul Pharmacol Ther, May 1.
20. Erdniset, N., Morad, Y. (2017). Treatments for Slowing the Progression of Myopia. Harefuah, Nov;156(11):720-724.
21. Landrum, J.T., Bone, R.A., Joa, H., Kilburn, M.D., Moore, L.L., et al. (1997). A one year study of the macular pigment: the effect of 140 days of a lutein supplement. Exp Eye Res, Jul;65(1):57-62.
22. Tong, N., Zhang, W., Zhang, Z., Gong, Y., Wooten, B., et al. (2013). Inverse relationship between macular pigment optical density and axial length in Chinese subjects with myopia. Graefes Arch Clin Exp Ophthalmol, Jun;251(6):1495-500.
23. Tanito, M., Obana, A., Gohto, Y., Okazaki, S., Gellermann, W., et al. (2012). Macular pigment density changes in Japanese individuals supplemented with lutein or zeaxanthin: quantification via resonance Raman spectrophotometry and autofluorescence imaging. Jpn J Ophthalmol, Sep;56(5):488-96.