Blindfolds are a covering that goes over the slave's eyes, preventing them from seeing what is occurring. Because the slave has lost the sense of sight, her other senses become heightened. She is more easily aroused by touches and can be excited by the Master or Mistress moving around and simply not knowing what will occur next.
Punishments can also be enhanced with blindfolds because the cane or hand comes as a surprise. Hard, soft and erotic can be alternated without the slave knowing what is coming giving the Master or Mistress more control and a more erotic session for the dominant and their submissive.
Hoods are similar to blindfolds, but cover the whole head. Unless the hood is very thin (like spandex) it will normally have mouth or nose holes for breathing. Hoods may or may not have mouth or eye holes to allow the slave to participate in the BDSM session. In addition to their bondage role, hoods are also popular due to their appearance and the way the can cover a slave.