Ipad screen 'greying out'?

When reading an instructables article on my ipad after 2 to 3 minutes the screen greys out and I get unwanted adverts/links which I can cancel with the X at the top after 2 cancellations the X no longer appears and I have to go out and then restart the article. Any ideas?

AryaG56 days ago

I JUST KNOW THAT FOR AVOIDING ANY ANNOYING ADDS U CAN GO TO AIRPLANE MODE

iceng16 days ago

Screen darkening is usually a function of ambient background light.. Try brightening your reading space..

As for annoying ads on free sadw, you may have to by the full ap..