Appears matters in general, yes.
It also depends on the industry and the position.... If you're there to work at a fashion retail and the job description requires you to be hip and cool and funky, then sure, wear it if thats your style.
Even in IT, some total techy geniuses with little or no client interaction in the job can get away with it simply because they are too good and their appearance doesnt matter to the employer as long as they are good at what they do...
Most other times, you would be expected to dress formally and properly according to a situation.
To me personally, it matters. I would not hire a person who hasnt bothered making an effort to look professional or lacks basic grooming. It doesnt take much really,, so theres no excuse.