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YOU CAN TURN AN OLD MONITOR INTO A SCREEN THAT ONLY YOU CAN SEE

Turn an old LCD monitor into a screen only you can see — everyone else sees plain white.

by dimovi (Instructables) and brusspup (YouTube)

FULL CAD BOM FIRMWARE DOCS

DisplaysWorkshop

difficulty
●●●○○
time
an afternoon
license
license not specified
repo
repo 0 stars

WHAT YOU’LL NEED

Videos
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COMPAREE VERDICT

This is one of those tricks that looks like magic until you understand polarization, then it is just clever physics. An LCD panel creates its picture by rotating polarized light through liquid crystals. The front polarizing film is what turns that rotation into an image your eyes can see. Peel it off and the screen looks uniformly white to everyone in the room, because the light is still polarized but your eyes cannot decode it. Cut that same film to fit a pair of cheap sunglasses and whoever wears them sees the picture again — nobody else does. brusspup demonstrated it with a 20-dollar pawn shop monitor; dimovi's Instructables page walks through the steps with photos. The entire build is glasses, a craft knife, solvent to clean adhesive, and a sacrificial monitor. What will go wrong: the film can tear as you peel it, the monitor you pick might have a bonded film that cannot be removed, and the solvent needs proper ventilation. This is not a weekend electronics project; it is a one-way modification of a piece of hardware you are prepared to lose. If you have an old monitor you were going to scrap anyway and you want a party trick that makes people check their own eyes, this is a legitimate hour well spent. If you need a privacy screen for actual work, buy a commercial one — this is a demonstration, not a security tool.

GOOD TO KNOW

  • —The Instructables page by dimovi is a photo-led walkthrough with brief notes, CC BY-NC-SA. No commercial use.
  • —brusspup's YouTube video (over 8 million views) shows the whole process with a 20-dollar pawn-shop monitor, and its description has detailed written steps.
  • —No bill of materials, no file downloads, no CAD. This is a hardware modification using parts you already have or salvage.
  • —Works only on older LCD panels whose front polarizing film can be physically removed. Many newer monitors bond the film to the glass and cannot be separated without destroying the panel.
  • —The modification is destructive: if the film tears or you pick the wrong monitor, the screen is ruined.
  • —The licence (CC BY-NC-SA) forbids commercial use of the instructions.

Parts to buy

4 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Old LCD monitorFind
  • Cheap sunglasses or safety glassesFind
  • Solvent (paint thinner or similar)Find
  • Craft knife or box cutterFind

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Can I build this?

Printnothing required
Buyan old LCD monitor (preferably from a pawn shop or e-waste pile), cheap sunglasses or safety glasses, solvent (paint thinner or similar), craft knife or box cutter
Toolscraft knife, solvent, good ventilation, patience
Skillscomfort working with solvents and sharp blades, willingness to ruin a monitor
Timeone to two hours if the film cooperates, more if it tears
Cost$, dominated by the monitor if you have to buy one (10-20 dollars used)
SafetySolvent vapors — work outside or in a well-ventilated space. Sharp blades. The film can shatter if the panel is cracked. No mains voltage work if the monitor is unplugged and disassembled first.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

Amazing Secret Monitor! (How To) - brusspup

The original demonstration video, over 8 million views. Shows the process with a 20-dollar pawn-shop monitor, and the description has detailed written steps.

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Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the Instructables page (Photo walkthrough by dimovi, CC BY-NC-SA. This is the primary written guide.)
  2. 2.Watch brusspup's video (The clearest demonstration of the process and the result; read the written steps in the video description too.)
  3. 3.Source a sacrificial monitor(Older panels work best. If the front film is bonded to the glass, this will not work. Pawn shops and e-waste piles are the usual sources.)
  4. 4.Test the film removal on a corner(Before committing, try peeling a small corner. If it lifts cleanly, proceed. If it splinters or refuses to separate, stop.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • Not all LCD panels have a removable front polarizer. Many newer monitors bond the film to the glass and cannot be separated without destroying the panel. You will not know until you try.
  • The real risk is damaging the LCD glass while cutting and peeling. Cut gently along the edges and peel slowly. If the film tears, you can make the glasses from new polarizing sheet instead, as brusspup did.
  • Solvents like paint thinner produce vapors. Work outside or in a space with real airflow, not a closed room with a window cracked open.
  • The film must be oriented correctly in the glasses. If you mount it 90 degrees off, it blocks the image instead of revealing it. Test the orientation before cutting.
  • This is a demonstration, not a security tool. Cameras can still see the screen if their sensor has no polarizing filter, and anyone can borrow your glasses.
  • The screen will look washed out and lower contrast even with the glasses on, because you have removed one of the optical layers the panel was designed with.

Does this work on any monitor?

Not every one. It only applies to LCD monitors, and the creators note it may not work with some of them, so use a monitor you do not mind losing and test a corner first.

Can I use this for actual privacy at work?

Not reliably. Cameras without polarizing filters can still see the screen, anyone can borrow your glasses, and the image quality is degraded. Buy a commercial privacy filter if you need real security.

What if the film tears while I am peeling it?

The monitor itself does not need the film any more, so a torn film is not fatal: brusspup made his glasses from new polarizing sheets he bought online. What can ruin the monitor is damaging the LCD glass itself with the knife or too much pressure, so peel slowly and gently.

Do I need special glasses?

No. Any cheap sunglasses or safety glasses work, as long as you can remove the original lenses and mount the polarizing film in their place.

How much does this cost?

If you have an old monitor already, almost nothing — just solvent and a pair of cheap glasses. If you have to buy a monitor, 10-20 dollars from a pawn shop or secondhand store.

Is the modification reversible?

Treat it as one-way. The original film and its adhesive will not go back on cleanly; brusspup suggests a skilled repairer might fit a replacement polarizing filter, but plan on the monitor staying a privacy screen.

Community builds

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Discussion1

FROM THE COMPAREE TEAM

brusspup did this with a monitor he bought from a pawn shop for 20 dollars, and the film either peels cleanly or it does not — you will not know until you try. What is the oldest monitor you have that you would be willing to sacrifice?

CompareeTEAM13d agoedited

Practical notes from our verification: this is one of the most-viewed DIY optics tricks on YouTube (over 8 million views on brusspup's video), and both sources give written steps: dimovi's Instructables page in eight short photo steps, and brusspup in his video description. The single biggest variable is the panel: you cut along the edges and peel the polarizing and anti-glare films off, then clean the adhesive with a solvent such as paint thinner, which also attacks the plastic frame. Go slowly, because damaging the LCD glass is what actually ruins the monitor. For the glasses, dimovi reused the peeled film while brusspup bought new polarizing sheets; either way the angle matters (brusspup had to turn his 45 degrees). The Instructables guide is CC BY-NC-SA, so this is a personal build. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

dimovi (Instructables) and brusspup (YouTube)

dimovi published the photo-led Instructables page under CC BY-NC-SA. brusspup's YouTube demonstration has 8 million views and is the reason most people know this trick exists. Neither is selling anything; this is a classic internet how-to.

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