Step 1: Understanding the concept.
The power of a lens is inversely related to its focal length. A thick lens has a slightly longer focal length compared to a thin lens of the same curvature, and therefore, its power is lower than that of the thin lens.
Step 2: Analyzing the statement.
The statement is True, as the power of a thick lens is indeed smaller than the power of a thin lens, due to the difference in focal lengths.
Step 3: Conclusion.
The correct answer is True, as the power of a thick lens is smaller than that of a thin lens.