Why is my phone not touch sensitive anymore?
Cleanse your screen
Regularly cleaning it with soft-cloth or cotton-buds dipped in cleansing-solutions is the ideal way to eradicate the dirt and debris from the screen. Also, using some kind of protection like a screen-guard or screen-protector can keep your screen sensitive enough.
Why is my phone not responding to touch iPhone?
If your iPhone's touchscreen is not working, first try to force-restart the phone. Make sure your touchscreen is clean and dry so it can sense your fingertips. Remove cases or screen protectors that may be interfering with the touchscreen.