Difference between 对 and 双
From &quot;Chinese: A Comprehensive Grammar&quot; (Routledge):

一对夫妇 &quot;a married couple&quot;
一对枕头 &quot;a pair of pillows&quot;
一对耳环 &quot;a pair of ear-rings&quot;
一双手 &quot;a pair of hands&quot;
一双眼睛 &quot;a pair of eyes&quot;
两双鞋 &quot;two pairs of shoes&quot;
三双袜子 &quot;three pairs of socks&quot;
The difference between 对 and 双 seems to be that the former emphasizes complementarity while the latter indicates functioning together.

(Anecdotally, it's been my experience that, due to influence from Cantonese, 对 is much more common in the south even when 双 would be &quot;correct.&quot;)