You have to be careful how you use this word "accessible" in the arts. In the art world, it will automatically be interpreted to mean that the form and content of the work make it easy for the general public to appreciate it. In this context, this often carries negative connotations... that a work relies on tried and true formulas, familiar stories and ideas and does not challenge the audience in any way. Such a work is said to "pander" to its audience, giving the audience what it wants, as opposed to expressing an artist's personal vision. And, there is a bit of a tendency toward elitism in the arts; inaccessibility makes for a sense of exclusivity. On the other hand, rarely (though not never) is the artist simply trying to be difficult. Artists are often beckoning us into unfamiliar territory, and to follow their lead requires some effort on our part, precisely because the terrain is unfamiliar.
So when working through ways to make artworks accessible to those with mobility or sensory impairments, it is important to find ways to remove the barriers to access erected by the impairments themselves, while retaining the challenges the work was intended to pose. If the challenge has not been maintained, then the work has not been made accessible... it has disappeared.
Perhaps the most difficult task one faces when making a work accessible (in either sense of the word) is to prevent this disappearance. Something will be lost in the translation. We need to develop a notion of sufficiency: we must be able to balance whether the result is sufficiently accessibility on one hand, and the whether the result is still sufficiently true to the most important aspects of the original on the other. There will be cases where a solution cannot be found. The approach must be pragmatic, and yet deeply respectful of the intentions of the creator and the often delicate balance of forces that define the work.