Round implants are symmetrical discs of implant, the same shape all the way around. They are the most widely used shape worldwide.
What they do
Round implants add volume across the whole breast, including the upper pole (the top of the breast), which can create a fuller, more "augmented" look or, with the right profile and placement, a natural one. Because they are symmetrical, rotation does not change their appearance — a practical advantage.
Who they suit
Round implants suit a wide range of patients and goals, from subtle enhancement to more obvious upper-pole fullness. The final look depends heavily on the profile chosen, your existing tissue and the placement. See also round vs anatomical.