Under what circumstances can astigmatism worsen?

Under normal circumstances, worsening astigmatism is mostly related to eye-use habits, ocular conditions, and external factors, primarily including poor visual habits, eye trauma, ocular diseases, abnormal growth and development, and improper eyeglass prescription. The specific analysis is as follows:

1. Poor eye-use habits: Prolonged near-work activities, such as continuously using smartphones or computers for several hours, can cause sustained tension in the muscles around the eyes, leading to gradual changes in corneal shape. Tilting the head, squinting, or lying down while reading or viewing objects creates uneven pressure on the eyeball, increasing corneal irregularity and thereby raising astigmatism levels—this is particularly common among adolescents.

2. Eye trauma: Physical injuries such as impacts or scratches to the eye may damage the cornea or lens. After a corneal laceration heals, scar tissue may form, altering the cornea's original refractive shape. Lens dislocation disrupts the optical balance of the eye. Both situations can lead to sudden and often significant increases in astigmatism.

3. Ocular disease influence: Keratoconus is a classic condition that causes progressive astigmatism. In affected individuals, the cornea gradually thins and bulges forward, resulting in rapidly increasing astigmatism, which may even lead to blindness in severe cases. Additionally, inflammatory conditions such as keratitis and corneal ulcers compromise corneal tissue integrity; irregular lesions left after healing can also cause persistent increases in astigmatism.

4. Abnormal growth and development: During adolescence, the eye undergoes rapid development. Conditions such as ptosis (drooping eyelids) or imbalanced extraocular muscle strength can exert continuous traction on the eyeball, leading to irregular development of the cornea or lens. Astigmatism caused by such developmental abnormalities tends to progressively worsen with age, requiring timely intervention to control its progression.

5. Improper eyeglass prescription: Inaccurate refraction testing or wearing glasses with incorrect prescriptions can keep the eyes in a constant state of fatigue. To adapt to incorrect optical correction, the eye may unconsciously alter its shape, further exacerbating corneal irregularity. Moreover, optical center misalignment in low-quality lenses can continuously irritate the eye, contributing to increased astigmatism.

To maintain eye health, it is important to adopt proper reading and writing postures, avoid prolonged near-vision tasks, and have regular vision checkups. Adolescents and individuals at high risk for keratoconus should undergo more frequent examinations. With scientific interventions and appropriate corrective measures, the progression of astigmatism can be effectively slowed, preserving long-term visual health.