I've been trying to homebrew an Eldritch Invocation that grants the Warlock blindsight, but I'm not sure how far this blindsight should extend. I initially thought to compare it to the pre-existing invocation Devil's Sight, which grants 120 feet of darkvision through magical and non-magical darkness, but blindsight is (obviously) far superior to darkvision, so I deserted that comparison.
Here is the current form of this Eldritch Invocation:
Eyes of the Ooze
You gain blindsight that reaches up to 15 feet.
Is this Eldritch Invocation balanced?