Hi Maria,
I have both directed and acted in Wait Until Dark, and it remains one of my favorite plays. Here are some tips and lessons we learned.
Your rehearsal space must reflect the set exactly. This is Susy's home and she knows it foot by foot... If it's 12 steps from the couch to the sink, you must take 12 steps every time, make sense? She finds her way easily around it. She only picks up a cane when she is about to go outside.
Rehearsing blindfolded is good for awhile but don't rely on it. It tends to make you want to close your eyes, a habit which you will then have to break later. When walking, pick a spot and walk straight ahead, only turn your head if you hear something to distract you. This is actually a good exercise, and we worked it at rehearsals, having our Susy walk back and forth across the space, turning her head only when someone made a noise to either side. What we learned is that most people don't always turn the right way at first but she would.
Looking ahead also lets your peripheral vision glance down. Blind people DO blink and they DO move their eyes. Spend some time talking to one if you can. You will find they are usually looking in the direction of your face, where they hear the sound from, when you speak. Very few do the Stevie Wonder bobble head thing.
Wear shin guards. Our Roat left a chair half a foot out of position and I'll be damned if our Susy didn't walk right into it and fall over it. He felt so bad, he brought her coffee every night for the rest of the run. This could save you some money!
Finally, for your actual audition, try this... we never focus on the auditors during a song or monologue, right? Shift your focus a little off intentionally, especially over the head of the one who has done the most talking. Keep your focus a little 'off', and when they speak, pause a beat and then focus as if locating them. That's what won ours her part.
Break a leg!
Best regards,
Joe
Currently rehearsing: Taming of the Shrew