The good thing about today’s technology is that it helps our work easier, and one of the examples here is the optical margin alignment in typesetting.
The purpose of the optical margin alignment is to create a neater text horizontal alignment, which is more about aesthetic consideration than a solid true or wrong guideline in typography.
Since the negative space contained in the punctuation type block can create an uneven margin than other blocks, this function is to squeeze out those extra space to help designers creating a more visually compelling layout.
What does this feature do is basically extending the text line horizontally to avoid vertical alignment between text and punctuations like quotation marks on different lines inside text boxes, the benefit is more obvious when the texts are set in justified or flush left.
Considering how much work to take to approach this in the manual type setting days, you will appreciate more about this helpful feature.
The Optical margin alignment option is available in both Adobe InDesign and Illustrator. You can find it under “Type/Story” in InDesign and “Type” in Illustrator.