VERTICAL CHOPPING: It is so-called as the movement between the two hands is in a vertical plane. A good purchase on the nucleus is much more important here than in horizontal chopping. In the latter, the nucleus is compressed between the two instruments moving towards each other, whereas in vertical chopping, forces act against each other as the phaco tip holds the nucleus up and the chopper depresses downwards into the nucleus to cleave it. While embedding, it should be made sure that the phaco tip is completely occluded by the nucleus. This can be attained using traditional ultrasound with burst mode and high vacuum levels. A sharp chopper should be used to prevent a break of occlusion of the phaco tip.In dense nuclei the crack may not propagate throughout and the nucleus needs to be rotated 180 degrees to repeat the chop from the other side. Each hemi-nucleus is then similarly chopped into smaller pieces. In hard brown cataracts, the posterior leathery plate has to be separated before the quadrants can be lifted out of the capsular bag. Vertical chopping is completed and the pieces are then lifted out one-by-one to be emulsified in the anterior chamber.