Not 100%
Not even close. Have to recommend  a Manta mask for the closest thing I've seen to complete darkness  if that is what you want. I've use a lot of sleep masks over the past 20 years. I used Hearos for years but they stopped making them.  The Manta is 30 bucks but looks like it will hold up at least twice as long as most others.
Rating: 1 stars