there said it. http://steamcommunity.com/id/SoFGR/screenshot/505821122932526270
for those who don't know :
this feature has been anncounced since late 2009, when RO2 was still in early alpha stage, these little grey dots try to simulate peripheral vision, helping you detect thing that are moving outside your FoV.
problem is, it only works on enemy soldiers !! most of the time it feels way too cheap and immersion breaking ! you can abuse this feature and get many "unfair" kills, your enemies can abuse it as well and counter your flank with ease !
since classic mode is pretty much dead now, i suggest everybody to play on custom servers like RGN semper fi etc, 99% of custom server have this setting set to OFF, while "realism" server has this setting enabled all the time
custom servers can be still ranked and allow you to use your unlocks etc
let "realistic" mode die until they fix it !