of myopia showed behavioral intervention (counseling to spend more time outdoors and less time with near-work) to be favored by 25% of specialists, usually in addition to medications. glasses and contacts the use of reading glasses when doing close work may improve vision by reducing or eliminating the need to accommodate. altering the use of eyeglasses between full-time, part-time, and not at all does not appear to alter myopia progression. the american optometric association's clinical practice guidelines found evidence of effectiveness of bifocal lenses and recommends it as the method for "myopia control". in some studies, bifocal and progressive lenses have not shown differences in altering the progression of myopia compared to placebo. in 2019, contact lenses to prevent the worsening of nearsightedness in children were approved for use in the united states. this "misight" type claims to work by focusing peripheral light in front of the retina. medication anti-muscarinic topical medications in children under 18 years of age may slow the worsening of myopia. these treatments include pirenzepine gel, cyclopentolate eye drops, and atropine eye drops. while these treatments were shown to be effective in slowing the progression of myopia, side effects included light sensitivity and near blur. other methods scleral reinforcement surgery is aimed to cover the thinning posterior pole with a supportive material to withstand intraocular pressure and prevent further progression of the posterior staphyloma. the strain is reduced, although damage from the pathological process cannot be reversed. by stopping the progression of the disease, vision may be maintained or improved. treatment glasses are commonly used to address near-sightedness.the national institutes of health says there is no known way of preventing myopia, and the use of glasses or contact lenses does not affect its progression, unless the glasses or contact lenses are too strong of a prescription. there is no universally accepted method of preventing myopia and proposed methods need additional study to determine their effectiveness. optical correction using glasses or contact lenses is the most common treatment; other approaches include orthokeratology, and refractive surgery.: 21–26 medications (mostly atropine) and vision therapy can be effective in addressing the various forms of pseudomyopia.compensating for myopia using a corrective lens. glasses and contacts prismatic color distortion shown with a camera set for near-sighted focus, and using –9.5 diopter eyeglasses to correct the camera's myopia (left). close-up of color shifting through corner of eyeglasses. the light and dark borders visible between color swatches do not exist (right). corrective lenses bend the light entering the eye in a way that places a focused image accurately onto the retina. the power of any lens system can be expressed in diopters, the reciprocal of its focal length in meters. corrective lenses for myopia have negative powers because a divergent lens is required to move the far point of focus out to the distance. more severe myopia needs lens powers further from zero (more negative). however, strong eyeglass prescriptions create distortions such as prismatic movement and chromatic aberration. strongly near-sighted wearers of contact lenses do not experience these distortions because the lens moves with the cornea, keeping the optic axis in line with the visual axis and because the vertex distance has been reduced to zero. surgery refractive surgery includes procedures which alter the corneal curvature of some structure of the eye or which add additional refractive means inside the eye. photorefractive keratectomy