The Eight-chopper I was first developed to perform the eight-chop technique. The prechopper used for the prechop technique, in which the lens nucleus is divided into four sections, has a large tip that is not suitable for operation in the lens capsule, as in the eight-chop technique, where the lens nucleus is divided into eight sections. Therefore, we reduced the size of the tip to 3.2 mm in length and 1.4 mm in width, and made the leading edge sharper. The completed Eight-chopper I is easy to operate within the eye and can divide the lens nucleus without difficulty. The usefulness and effectiveness of the surgical method using the Eight-chopper I were presented at the Japanese Society of Ophthalmic Surgery in 2009.

The Eight-chopper II was developed by further downsizing and sharpening the tip of the Eight-chopper I. The length and width of the tip are 2.5 mm and 0.8 mm, respectively. The tip is 2.5 mm long and 0.8 mm wide, and its leading edge is sharpened. The tip is angled so that it can be inserted vertically into the lens nucleus. The Eight-chopper II can be used to perform the eight-chop technique for harder nucleus. The usefulness of the Eight-chopper II was presented at the Japanese Society of Ophthalmic Surgery in 2011.

In the Eight-chop technique, the lens nucleus must be divided by the Lance-chopper when the lens nucleus is hard. However, the conventional prechopper (universal prechopper, D) is difficult to operate because the tip is long and difficult to insert. The short and sharp tip of the Lance-chopper allows for easy intraocular manipulation and penetration into the lens nucleus, while the wide tip effectively presses on the cross-section of the lens nucleus to enlarge the fissure. The surgical procedure using the Lance-chopper was presented at the Japanese Society for Ophthalmic Surgery in 2019.