If there's not enough contrast between the elements on your screen, try using a high contrast theme. To scale up everything on your screen, select the Start button, then select Settings > System > Display, and change the Scale drop-down menu under Scale & Layout to a larger percentage. Use the slider next to Text size to make just the text on your screen larger.
To adjust the size of text, apps, and other items, select the Start button, then select Settings > Accessibility > Text size.
