Yes, barcode scanner is bad for eyes. Because the laser beams in the scanner could either temporarily affect your vision and it depends on how strong the laser beam is. That's why you can see warning labels slapped near some scanners. So please do not to look directly at the laser beams from scanner.
The radiation let out by the barcode scanner is bad for eyes for sure. All the electronic product have this side effect.
And barcode scanner take more infrared ray which can cause telangiectasia, overburden our eyes, etc. So it's worse than lots of digital products.
Try to avoid the scanner when you pay for the bills at any supermarket.
Frequently staring at the barcode scanner in a close distance is bad for eyes, because the light of barcode scanner is too strong, which can hurt our eyes. But you do not need to worry about it, because in our daily life, the times of we use barcode scanner is rarely, and the distance between barcode scanner and our eyes is more than 0.5 meter, which is very safe.