Intensely focused on work when I suddenly see manager behind me

Question

I work as a software developer in a bullpen workplace, which looks something like the below picture¹:

Since it is difficult to have prolonged periods of concentration in this environment, my preferred approach to tackle difficult problems is to have short periods of intense concentration, when I put on earplugs and headphones and set the instant messenger status to "Busy" (or even shut it down entirely).

The drawback to this approach is it is impossible for me to tell when someone walks up to my desk. A couple of months ago, when I was in the middle of one such session of intense focus, I felt a gentle tap on my shoulder, which startled me, and I almost got a panic attack.

After a few seconds of fidgeting in my chair, I turned around and saw my manager standing behind me. He had been standing there for over 2 minutes calling my name, and then finally decided to tap my shoulder to get my attention.

My goal is to be better prepared to handle such situations in future to avoid getting a real panic attack, which I am pretty scared of. My social skills are average at best. How should I respond in these situations:

1. When I suddenly realize that the manager is standing behind me, what should I do or say to him which does not cause any awkwardness?
2. How can I communicate to him to not "sneak up" on me avoiding potential panic attacks? I don't want him to think I am using this an excuse to prevent him from seeing potentially NSFW items appearing on my monitor.

Update

I have already tried using mirrors, and they don't work for me. Every time someone wearing flashy/bright clothes moves behind me, it registers on my peripheral vision, which distracts me and I lose focus.

It also reflects the lights from monitors placed me, which is a distraction by itself, but also leads to another issue. I am several years senior to the coworkers seated behind me, and they thought the mirror was meant to monitor them, which was the main reason I removed it.

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¹ Image source: http://www.goodearthplants.com/quiet-down-workplace-distractions-plants-increase-productivity/

Answer 1

When I suddenly realize that the manager is standing behind me, what should I do or say to him which does not cause any awkwardness?

"Hey Joe, I am sorry I did not hear you, was really focused on this report. What can I help you with?"

You can tell when someone is really focused on a task, your manager should understand this and don't make a problem out of you being deeply engaged in your work.

How can I communicate to him to not "sneak up" on me avoiding potential panic attacks?

Give that your manager is already aware of situations like this startling you (as the situation you mention), you could just be clear and honest to him. You could try something like:

"Hello Joe. About that last time you came to my desk, I got really startled when you tapped my shoulder, as I was deeply focused on my work. I hope that did not cause any inconveniences. Could you approach me in future situations in a more discrete or soft way? I am always willing to answer to your questions, but I would prefer not to be startled in such way."

You could ask your manager to approach you on the front side of your desk, so you will most probably perceive him approaching. I also think a mirror could help you in case people approach you from the back side, as mentioned in @mutt 's answer.

Another option could be to implement some sort of "traffic light" (via post-its or something more elaborated), that indicates your colleagues how critical is the task you are performing, so they can evaluate when to ask their questions.

Answer 2

A simple solution is to get a small mirror and put it on the side of your monitor. This works well so you can completely zone, but you will visually see someone behind you if they walk up and stand there.

As far as "sneaking" he probably just walked up to you like anyone else and didn't sneak. As far as what to say, "I'm sorry I didn't see you there, I was totally focused on the task and missed you standing behind me."

Edit based on comment: You can get a motion sensor which you can install to your computer with a popup notification. Put the motion sensor in a place and gauge it's range so that it only activates when someone is directly behind you.

Like this that turns a light on when it picks up the motion small motion light put the light near your peripheral or under the desk and the motion for directly behind you. Just make sure it doesn't shine in other people's faces when it activates.