What is Astigmatism?
Astigmatism is a common refractive error caused by an irregular shape of the cornea or lens, which prevents light from focusing correctly on the retina and affects visual clarity. Normally, the cornea and lens have a smooth, spherical shape. However, if these structures have irregular curvatures, astigmatism may occur.
Can Mobile Phone Light Cause Astigmatism?
Many parents worry that using a mobile phone near their child at night might affect their eyesight or even cause astigmatism. In reality, the light emitted by a phone screen does not directly lead to astigmatism. The condition is related to the structure of the eye rather than exposure to light. Even though electronic screens emit light into the eyes, they do not alter the physical structure of the cornea or lens. However, prolonged exposure to strong or dim light can cause eye fatigue, potentially exacerbating existing astigmatism symptoms.
Behaviors That May Trigger or Worsen Astigmatism
While mobile phone light itself does not directly cause astigmatism, certain habits can increase the risk of developing or worsening the condition. Parents should pay attention to the following:
- Frequent eye rubbing: Children who frequently rub their eyes may apply pressure that alters the shape of the cornea, leading to or worsening astigmatism. Those with existing astigmatism may develop habits such as squinting, tilting their heads, or rubbing their eyes to see more clearly, which can further strain the cornea and affect vision.
- Prolonged use of electronic devices or screen time in dark environments: Although electronic screens do not directly cause astigmatism, excessive screen time can lead to eye fatigue, which may impact the stability of corneal shape and worsen existing astigmatism. Using screens in dim lighting can also disrupt tear film stability, leading to dryness and potentially accelerating myopia progression.
Does Childhood Astigmatism Require Correction?
Astigmatism in children is influenced by genetic factors, and newborns or premature infants often have higher degrees of astigmatism. However, most cases improve or disappear as the eyes develop. Studies show that while 41.6% of three-month-old infants have astigmatism of 100 diopters (D) or more, this percentage drops to 4% by the age of three.
If astigmatism is severe, exceeds the normal physiological range, or affects visual development, intervention is necessary. Correction is generally recommended under the following conditions:
- Astigmatism of 300 D or more in infants under one year old
- 250 D or more in children aged one to two years
- 200 D or more in children aged two to three years
- More than 150 D in children older than three years
- A difference of 200 D or more between both eyes
The primary method for correcting astigmatism is wearing prescription glasses. While glasses cannot eliminate astigmatism, they help minimize its impact on visual development. If properly managed, some children may later no longer need glasses.
How to Prevent Astigmatism from Worsening
Maintaining good eye health habits can help prevent astigmatism from progressing. Parents can take the following measures:
- Schedule regular eye exams to monitor visual development and detect issues early.
- Encourage children to avoid rubbing their eyes, as this can put pressure on the cornea and affect its shape.
- Increase outdoor activities, as exposure to natural light helps maintain eye health and reduces eye strain.
- Limit screen time and avoid using electronic devices in dark environments to minimize eye fatigue.
Key Takeways
Astigmatism is common in children, and in many cases, it improves naturally as they grow. However, parents should remain vigilant about their child’s eye health and encourage proper eye care habits. If any abnormalities are noticed, seeking medical advice promptly ensures that vision development is properly managed.
References:
[1] Chinese Medical Association Ophthalmology Branch Strabismus and Pediatric Ophthalmology Group, Chinese Medical Doctor Association Ophthalmologist Branch Strabismus and Pediatric Ophthalmology Group. Chinese Expert Consensus on Amblyopia Prevention and Treatment in Children (2021). Chinese Journal of Ophthalmology, 2021, 57(5): 336-340. DOI: 10.3760/cma.j.cn112142-20210109-00014.
[2] Gwiazda J, Grice K, Held R, McLellan J, Thorn F. Astigmatism and its relation to emmetropization in children. Optometry and Vision Science, 2000; 77(12): 615-620. DOI: 10.1097/00006324-200012000-00009.
[3] Read SA, Collins MJ, Carney LG. A review of astigmatism and its possible implications for early refractive development. Eye & Contact Lens, 2007; 33(3): 177-185. DOI: 10.1097/01.icl.0000243176.32924.f3.
[4] Heidary G, Ying GS, Maguire M, Quinn G, Kulp MT, et al. Prevalence of Astigmatism in a Population-Based Sample of Preschool Children. Investigative Ophthalmology & Visual Science, 2010; 51(2): 597-603. DOI: 10.1167/iovs.09-3990.
[5] Read SA, Collins MJ, Carney LG. The influence of eyelid pressure and ocular surface forces on corneal topography. Investigative Ophthalmology & Visual Science, 2007; 48(3): 1238-1248. DOI: 10.1167/iovs.06-0867.
