Three quick tests to check if your traps are tight: raise your arm behind your back, tilt your head side to side, and use an eye chart to see if your vision changes as tension improves.
But first, what we want to do is get an assessment. So first thing you want to do is take your arm and reach up your back as far as you can and get an idea of how well you can reach there and what kind of tightness you have in that trapezius. You also may want to test your lateral neck range of motion, so tilting your head side to side. Make sure you're not rotating or extending your head, but actually just tilting. Also, make sure you use a Snellen chart or something to measure your vision. That way you can see if your vision improves while doing this as well.
Stop Stretching Your Neck. Try This Instead (It Might Improve Your Vision Too)
