Alignment creates visual connections, a sense of order, and hierarchy. It improves readability.
Horizontal rhythm keeps horizontal spaces between elements on a page consistent. In typography, horizontal rhythm impacts legibility.
Optical alignment in design refers to how we adjust UI for what “looks right” versus real measurements:
“Our eyes are weird organs that often tell lies to us. But if you know the peculiarities of human vision, you can construct more approachable and clean designs. Not only do type designers utilize optical tricks for creating readable and well-balanced fonts, but it’s also helpful for interface designers, who build user-computer interaction.” — Slava Shestopalov, Optical Effects in User Interfaces: An Illustrated Guide