The ornamental design for a keyboard for the visually impaired, as shown and described.
FIG. 1 is a top, front and side isometric view of a keyboard for the visually impaired in accordance with the invention, it being understood that the undisclosed views do not form part of the claimed design.
FIG. 2 is a top plan view thereof; and,
FIG. 3 is a cross-sectional view thereof taken along line-3-3 in FIG. 2 wherein it is indicated that the home row keys are recessed in relation to the other rows of keys.
The indicia shown in broken lines represent environment only and forms no part of the claimed design.