Grey translucent screen issue on iMac

Is your iMac an M1 iMac? If it is you're probably experiencing what many other M1 wonder are experiencing: the following topics illustrate the Silicon M1 iMac Display problem:

Screen Failure on 24-inch-iMac, M1, 2021 - Apple Community

Persistent horizontal lines appear on iMac Screen - Apple Community

Horizontal Lines on Screen of iMac, 24", 2021

Horizontal black lines covering bottom 3rd of 2021 M1 iMac screen

Grey horizontal patches on my M1 iMac 2021 model

Horizontal lines at the bottom of iMac(M1,2021) screen

Horizontal Lines on 2001 M1 iMac Display

M1 iMac Display vertex heating to scorching 55°C  — Seeking Advice on Escalation

Horizontal Lines on iMAC with M1 chip

Currently there is no Service Program for that issue but keep checking this website in case Apple instigates one: Apple Service Programs - Apple Support.  

Currently the only options are to:

1 - pay to have the screen replaced.

2 - get a 3rd party monitor and use it while darkening the iMac's screen.

3 - get a new Mac.

I wish I had better news to tell.

I am sorry, on the screenshot I don’t see any issues?

If there’s an issue that i cannot see, you can always try to boot your mac in the safe mode to see if the issues persist

Start up your Mac with Apple silicon in safe mode

1. On your Mac, choose Apple menu  > Shut Down.
2. Wait for your Mac to shut down completely. A Mac is completely shut down when the screen is black and any lights (including in the Touch Bar) are off.
3. Press and hold the power button on your Mac until “Loading startup options” appears.
4. Select a volume.
5. Press and hold the Shift key, then click Continue in Safe Mode.
6. The computer restarts automatically. When the login window appears, you should see “Safe Boot” in the menu bar.

If the issue do not persist in safe mode, the issue is most likely caused by an external piece of software.

If your screen resembles the ones at > Persistent horizontal lines appear on iMa… - Apple Community

Then your options are to have it repaired, use an external display or replace it with a new Mac.

see > Mac - Which Mac is best for me? - Apple