Scroll to the bottom and see if it’s enabled or disabled. To do that, go to Settings and Accessibility, then choose Display and Text Size. Double-Check That Auto-Brightness Is OffĮven if you think you already have Auto-Brightness turned off, it’s best to double-check to see if this is indeed the case. The screen is meant to become lighter when you’re outside in the bright sun and darker at night. This is a feature that will automatically adjust the brightness on your screen based on varying lighting conditions. Usually, when an iPhone’s screen continuously dims, it’s because Auto-Brightness is turned on. Fortunately, some fixes can stop your screen from dimming. Low Power mode, True Tone or Night Shift being enabled, and even your iPhone becoming overheated can all cause this problem. Your iPhone’s screen might grow dim for any number of reasons if Auto-Brightness is off. Why Does My iPhone Screen Keep Dimming with Auto-Brightness Off? What if Your iPhone’s Screen Is Still Too Dim?.Check to See if Reduce White Point Is On.Double-Check That Auto-Brightness Is Off.Why Does My iPhone Screen Keep Dimming with Auto-Brightness Off?.It’s important to know why this happens with your iPhone and how it can be fixed so you can get back to seeing your screen again. It’s frustrating and confusing when you know you have the Auto-Brightness feature turned off. You’re using your iPhone outside when the screen suddenly becomes overly dark.