Adjust brightness, text size, sounds, and haptics on Apple Watch
Adjust brightness and text on Apple Watch
Open the Settings app 
on your Apple Watch, then tap Brightness & Text Size to adjust the following:
Brightness: Tap the Brightness controls to adjust, or tap the slider, then turn the Digital Crown.
Text size: Tap Text Size, then tap the letters or turn the Digital Crown.
Bold text: Turn on Bold Text.
You can also make these adjustments on your iPhone. Open the Apple Watch app on your iPhone, tap My Watch, tap Brightness & Text Size, then adjust brightness and text.
Adjust sound
Open the Settings app
on your Apple Watch.Tap Sounds & Haptics.
Tap the volume controls under Alert Volume or tap the slider, then turn the Digital Crown to adjust.
Or, on your iPhone, open the Apple Watch app, tap Sounds & Haptics, then drag the Alert Volume slider.
Adjust haptic intensity
You can adjust the strength of the haptics—or wrist taps—Apple Watch uses for notifications and alerts.
Open the Settings app
on your Apple Watch.Tap Sounds & Haptics.
Choose Default or Prominent.
Or, on your iPhone, open the Apple Watch app, tap My Watch, tap Sounds & Haptics, then choose Default or Prominent.
Turn Digital Crown clicks off or on (Apple Watch Series 4 only)
On Apple Watch Series 4, you feel clicks when you turn the Digital Crown to scroll. To turn these haptics off or on, follow these steps:
Open the Settings app
on your Apple Watch.Tap Sound & Haptics, then turn Crown Haptics off or on.
Or, on your iPhone, open the Apple Watch app, tap My Watch, tap Sounds & Haptics, then turn Crown Haptics off or on.