The blue tape on our glass sliding door is at human eye level. The lower tape is at dog eye level. We did have a human walk into the door and break it years ago, and the dogs tend to go crazy when they see birds in the backyard and I don’t want them slamming into the glass (plate glass BTW; outlawed for this use in the USA 50 years ago).
Unfortunately, the pigeon paid no attention to either. RIP.