Large Dynamic Type: When you activate Larger Dynamic Type, the text inside a wide range of apps, including Calendar, Contacts, Mail, Messages, Music, Notes, and Settings, and even some third-party apps, is converted to a larger, easier-to-read size. Apps adapt to accommodate larger font sizes so text remains legible and clear as it grows. And you can choose bold text to make the text heavier across a range of built-in applications.
Increase Text Size
- Open the Settings app on your iOS device > Tap General > Tap Accessibility > Tap Larger Text.
- Toggle the switch Larger Accessibility Sizes to reveal bigger font options.
- Now drag the slider to select the font size you want.
Increase Screen Contrast
- Open the Settings app on your iOS device > Tap General > Tap Accessibility > Tap Increase Contrast from under the VISION category.
This opens the Increase Contrast window. From here you can manage the contrast related settings.
- Tap the Reduce Transparency toggle button. This reduces the transparency level of the objects’ background of your device to the optimal level, thus making them more clearly visible to the viewers. Optionally you can also enable the Darken Colors toggle button to further improve the visibility.
Source: https://www.razmobility.com/ios-built-in-accessibility/#learn-more