Master the NBEO Binocular Vision Challenge 2026 – See Success in Sight!

Meridional amblyopia happens when uncorrected astigmatism during early development creates persistent blur in a specific orientation. Astigmatism means the eye focuses light differently along different meridians, so one meridian can be consistently blurred while another remains relatively sharp. During the critical period of visual development, the brain may underdevelop high acuity for the blurred orientation, leading to reduced sharpness that is orientation-dependent. This is what gives meridional amblyopia its characteristic pattern: acuity is poorer for stimuli aligned with the blurred meridian rather than a uniform decline across all orientations. Correcting the astigmatism early allows the visual input to be more uniformly sharp, helping prevent or reverse this amblyopia. So stating that meridional amblyopia is caused by uncorrected astigmatism is accurate.