> If someone has a hypothetical medical device with a screen (do you have one in mind?) I’m sure the owners of such an establishment would seek to find ways to accommodate. It’s an edge case and not likely to impact the overall atmosphere.

I have a relative who has heart rhythm anomalies that uses an iWatch with an upgraded band (Kardia) for monitoring.

Prior to that it was a smart phone that had some ekg sensors that did a phone home/hospital if there were any anomalous readings and reporting periodic summaries (there was an occasional anomaly that was detected in an unrelated hospital stay but they didn't know how frequently this anomaly occurred - 1/week its a "be aware and continue to monitor" to 1/hour its a "go to the hospital and have some surgery - but it has to be done while the nerve is doing its thing").

The thing is that smart watches and phones are being used for real time monitoring of medal issues and they have screens.

Or even for a less problematic situation, I have my iWatch set to alert me if the decibel level is above a threshold. While a cafe is less likely to get above that level this is still something that I pay attention to and have occasionally found that a pub that I go to can get louder than I had otherwise realized.