TY - CHAP M1 - Book, Section TI - Strabismus A1 - Motley, W. Walker A2 - Riordan-Eva, Paul A2 - Augsburger, James J. PY - 2017 T2 - Vaughan & Asbury's General Ophthalmology, 19e AB - Under normal binocular viewing conditions, the image of the object of regard falls simultaneously on the fovea of each eye (bifoveal fixation), and the vertical retinal meridians are both upright. Strabismus is any ocular misalignment in which only one eye fixates with the fovea on the object of regard. (In everyday language, squint means partial closure of the eye to see more clearly, but sometimes it is used to mean strabismus.) Misalignment of the eyes may be in any direction—inward (eso-), outward (exo-), up (hyper-), down (hypo-), or torsional. The amount of deviation is the angle by which the deviating eye is misaligned. Tropia (manifest strabismus, heterotropia; Box 12–1) is strabismus present under binocular viewing conditions. Phoria (latent strabismus, heterophoria) is a deviation present only after binocular vision has been interrupted by occlusion of one eye. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1144468906 ER -