As described here:
https://civicrm.stackexchange.com/questions/4288/how-can-i-restrict-a-users-ability-to-edit-a-custom-field
The ability to permission custom fields to be edited or viewed is the same and is universal for all custom field sets and the permission a user is granted in regards to viewing or editing contacts.
Currently, it says
"NOTE: For Custom Data ACLs, the 'View' and 'Edit' operations currently do the same thing. Either option grants the right to view AND / OR edit custom data fields (in all groups, or in a specific custom data group). Neither option grants access to administration of custom data fields."