doric lenses cut-ball lenses Cut-ball microlenses are made from ball lenses and are widely used in endoscopy and microscopic applications. When complemented with glass spacers of appropriate thickness, cut-ball microlenses become excellent fiber optic collimators. The NA of these lenses is proportional to refractive index of the glass spacers. A special case of cut-ball lenses are half ball lenses. These lenses can be used as fiber-optics collimators. In order to accommodate different fiber-arrays pitch, the edge of the lens may be ground to a desired width.