Most privacy screen protectors use a form of micro louver technology that allows light from the display to pass through only at certain angles. Essentially how Venetian window blinds work, but at a microscopic scale. The filter layer is set to a narrow front angle, usually 60 or 90 degrees, and anyone looking at your screen from beyond that viewing angle won’t see anything.

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The best privacy screen protectors and what to look for

There are quite a few brands that make privacy screen protectors. There are some things you should know before buying one though.

• Micro louver technology – Some privacy screen protectors use some type of micro louver technology. These provide a better viewing experience than other options that are just darkened glass or film.
• Tempered glass or film – This is a personal preference with regards to the type of display protection you’re looking for. Both can have privacy layers. Finding full coverage with a tempered glass panel can be a touch difficult especially if the phone has a curved screen. Tempered glass is much better when it comes to protecting the display though.
• 2-way or 4-way privacy – A 2-way filter shows a darkened screen only in the portrait orientation. The obvious advantage here is that if you want to share something on your phone, all you have to do is turn the phone to landscape. However, if complete privacy is what you are looking for, 4-way privacy filters work in both orientations.
• Viewing angle – The viewing angle has to be narrow enough so that people standing or sitting next to you are out of range. If a viewing angle is too wide, it kinds of defeats the purpose of having a privacy screen protector. On the flip side, if it’s too narrow, it may impact your own viewing experience. You’ll have to face the screen head-on to make sure that you are able to see the screen properly. With most privacy screen protectors, the available viewing angle is usually 60 or 90 degrees.

Advantages

The most obvious advantage of using a privacy screen protector is in the name — privacy. Knowing that any sensitive information is safe from the prying gaze of bystanders is a big positive.

It isn’t just about privacy in public areas either. If a spouse, partner, or roommate gets annoyed at the fact that you are on your phone all night, a privacy screen protector helps here as well. It guarantees that they aren’t disturbed by the light from your phone, while you can continue to enjoy it without any issues.