nearsightedness

Nearsightedness, or myopia, is a common refractive error in which distant objects appear blurry while close objects are seen clearly. It occurs when the eye is too long relative to its optical power or when the cornea is too steep, causing images to focus in front of the retina rather than on it.

It typically begins in childhood or adolescence and may slowly progress. People with myopia may squint to see distant signs, experience eye strain, headaches, or fatigue after prolonged visual tasks.

Diagnosis is made through a comprehensive eye examination, including refraction testing to determine prescription and an assessment of the eye’s structure, such as retinoscopy and axial length measurement. An examination of the retina is often performed to rule out other eye diseases.

Causes and risk factors: Myopia results from a mismatch between the eye’s optical power and its length, often due to an elongated eyeball or a steep cornea. It has a substantial genetic component, with higher risk if one or both parents are myopic. Environmental factors, such as extensive near work and limited time outdoors during childhood, have been associated with progression.

Treatment options include corrective lenses (eyeglasses or contact lenses) to focus images on the retina. Myopia control methods aim to slow progression, including orthokeratology (specialized rigid contact lenses worn at night) and low-dose atropine eye drops in children. Refractive surgery, such as LASIK, PRK, or SMILE, permanently reshapes the cornea to reduce or correct refractive error, typically used in adults with stable prescription.

Prognosis and complications: Corrective lenses help maintain vision and daily functioning, but high myopia increases the risk of retinal detachment, myopic maculopathy, cataract, and glaucoma. Regular eye exams are important to monitor progression and detect early complications. Prevention strategies include outdoor time during childhood and balanced near work, though evidence varies.