Answer
Visual tracking of an object is a very complex process which involves six different kinds of eye movements. It is necessary to fix the moving object within the fovea and keep it there by making quick adjustments of the type that smooth muscles are incapable.
The movement of the eye in visual tracking is controlled by the four rectus muscles; the superior, and the inferior and inferior obliques. These are voluntary skeletal muscles which respond quickly to electrical excitation induced by visual stimuli.
Work Step by Step
Smooth muscles are not under voluntary control. They do not have neuromuscular junctions, and though they respond to many kinds of stimuli (including electrical ones) they are much slower to contract and much slower to relax than skeletal muscles. This makes them unsuitable for controlling eye movements in visual tracking.