Sometimes you really don’t want the people around you to see what’s on your laptop screen, so HP has come up with a solution. It’s developed a new screen that can cut off viewing angles with the press of a button, making it much harder for anyone on either side of a laptop to see what’s being displayed.

The feature works by preventing light from shooting off to the side. That way, when it’s active, you should only be able to see the laptop if you’re facing more-or-less straight on, within the the 70-degree arc right in front of it; 95 percent of light directed to either side of that is supposed to be cut off.

You might have seen something like this before: people already buy “privacy filters” and stick them onto their laptop screens to achieve this same effect. But there’s a big downside to that method: it’s mostly permanent, which means you’re stuck with a darker, harder-to-view laptop screen even when you’re in private.

It works, but the screen gets harder for you to read, too

What’s interesting about HP’s privacy filter is that it can be turned on and off by pressing a keyboard shortcut. That way you can leave it off when you don’t need it, so you’re not always staring at a dark screen.

The feature is called Sure View and was developed in partnership with 3M, which actually sells some of those stick-on filters. Starting in September, the Sure View screen will be available on two HP laptops: the EliteBook 1040 and EliteBook 840. It has a 1080p resolution and can support touch.

During a demo in a dimly lit room last week, the tech appeared to work relatively well. When it was off, the laptop screen was bright and clear, without any hint of a filter inside it. When it was turned on, the screen became very hard, though not altogether impossible, to view from the side. It was clear enough straight on; however, to get the full effect, HP automatically dims the laptop’s screen to a fairly dark level. That can make the screen harder to read even if you’re sitting right in front of the laptop.