Three-dimensional (3D) printing technology has evolved tremendously in recent years, but due to stringent requirements on surface finish and limited material selection for optical performance purposes, 3D printing optics is still lagging behind. This paper reports on a quantitative study on the printing process of optical lenses using acrylic and cationic combined commercial hybrid material. By utilizing its unique curing property with digital light process technology, we demonstrate the concept of continuous printing in the top-down light projection setup. Also, an equal thickness and equal arc combo method has been proposed and evaluated to further help smooth the surface finish. Millimeter-level spherical lenses have been successfully fabricated, and their optical performance has also been discussed.