The authors conducted a pilot study to investigate the effect of visual noise or background complexity on binocular summation in patients with strabismus. A target embedded in pixel noise was used. The study involved performance of a task detecting a luminance target measured at 0, 10 and 20udeg2 of visual noise for binocular and monocular conditions. Subjects included 10 with exotropia, 10 with esotropia and 13 controls. Overall, for esotropia and exotropia, a significant decrease in binocular summation was noted compared to controls. For exotropia alone, there was also a significant lower amount of binocular summation. Mean binocular inhibition (summation ratio <1) was at both noise levels. The authors conclude that strabismus can lead to decreased binocular summation and binocular inhibition.