A fluid jet is directed at tissue to erode tissue with a controlled amount of ablative energy of a jet. Embodiments as described herein can provide controlled removal of ocular tissue, and can remove a pre-defined volume having a pre-determined shape, for example. The accurate tissue removal as described herein can have many applications, such as removal of the lens for cataract surgery to more completely remove the cortex and nucleus of the lens and to separate layers of the lens. The length of an ablation depth extending from an opening that releases the jet can be controlled, and the angle and longitudinal position of the opening can be controlled together, in order to ablate a pre-determined volume of tissue having the surface profile.
