Minimum vision loss is seen in which cataract?

Blue dot cataract: It is also called cataracta punctata-caerulea. It usually forms in the first two decades of life. The characteristic punctate opacities are in the form of rounded bluish dots situated in the peripheral pa of an adolescent nucleus and deeper layer of the coex. Opacities are usually stationary and do not affect vision. However, large punctate opacities associated with coronary cataract may marginally reduce the vision.Ref. Khurana; 4th edition; Pg. 173