Crossword puzzle clue "it's difficult to see through"

It's difficult to see through

Actress who wore contact lenses she couldn't see through to play a blind woman in "All I See Is You": 2 wds.

Make it difficult to see where one thing begins

Hidden and difficult to see

"Difficult to see. Always in motion is the future" speaker

Difficult to get through

More difficult to get through to

Difficult (like wood hard to chop through?)