How can I make my tetras less timid?

I have three black phantom tetras in a 10 gallon tank, but everytime I approach the tank they all hide in a corner behind a ceramic ornament. I've had one of the tetras for three years and the others for 1-2. They will come out if I feed them, but they eat better if I walk away from the tank and watch them at a distance. Is there anyway I can gradually make the less timid?