You Can Read Without Your Glasses
When you buy a physical book, you’re stuck with the font size the author chose. And if they chose a really small size, you might have a hard time reading it.
With a digital book, on the other hand, you can change pretty much anything. You can choose the style of the font so it looks however you want.
Likewise, you can change the size of the font so you can read without glasses and without any struggles.