The choroid at its circular margin towards cornea has thickened ciliary body, which contains a number of circular, radial and oblique smooth ciliary muscle fibres. Six flattened, strap-like muscles, inserted by tendons upon the sclerotic coat of equatorial region of each eyeball in mammals, serve to rotate the later in different directions within its orbit for viewing objects at different distances and angles. These are four recti (superior inferior, medial and lateral) and two oblique muscles (superior and inferior).