As mruffruff mentioned if you wait too long they will not be able to remove them.

The whiskers help to navigate the dog quite a bit too like mentioned.

Try not to move furniture around.

Some people use scents to help their blind (or almost blind) pets (I've know people that do with cats, dogs & ferrets all with success).
Use all natural scents and only one for each catagory like.
For example put rose oil on anything that drops down, a step, a hole etc...
Use lavender oil for corners like walls, big furniture etc..
Use tee tree oil for favorite spots, a dog bed, blanket, crate etc...
BUT tee tree oil was an example. If you use this on you or your pet for any other reasons then by all means do not use that scent.

Try not to put 2 different drops too close together. You only need a small amount & only need to refresh it every 3-5 days or so (maybe more often like every other day at first). Obviously if you wash or rub against the area frequently you want to apply more drops there more frequently.