Among fifth and sixth grade children<unk>  is 13%. In studies that used standardized definitions of<unk> , investigators have reported a prevalence of 4.2% to 6% in school and clinic settings. The standard definition of<unk>  is exophoria greater at near than at distance, a receded near point of<unk> , and reduced<unk>  amplitudes at near.
Convergence insufficiency
Strabismus
Vertebrobasilar insufficiency
Papillary stenosis
Monotropism
Ecotropism
Vitreomacular adhesion
Solvent drag