With accent marks:
У семи́ ня́нек дитя́ без гла́зу.
~ Seven babysitters make the kid to lose an eye.
The more people take on one task, the less attention is paid to the task.
The closest English equivalent: too many cooks spoil the broth.
Other Russian proverbs
Without labor, you can not even catch a fish in the pond.
You can't help grief with tears.
Laws are not written for fools.
Crowded, but not aggrieved.
What goes around comes around.
Оne sees the mote in another's eye and ignores the log in his own.
Time for business, an hour for fun.
Patience and labor will grind everything.