'The eyes like quinine...'

Above is Van Gogh's famous, and still startling, portrait of Dr Gachet, the homoeopath and amateur painter who was Vincent's friend and protector during the final months of his life. In his collection of ekphrastic poems, 'Impressions' (published in the volume Between Here and Now), R.S. Thomas responds to the portrait...

Not part of the Health Service;
no-one to pass his failures
on to. The eyes like quinine
have the same medicative

power. With one hand
on cheek, the other
on the equivocal
foxglove he listens

to life as it describes
its symptoms, a doctor
becoming patient himself
of art's diagnosis.

Elsewhere in 'Impressions', Dr Gachet appears again, in Thomas's response to a Cézanne painting, Dr Gachet's House. Cézanne got to know Dr Gachet when he was staying in Auvers-sur-Oise in 1872 (18 years before Van Gogh's portrait). Though Cézanne dismissed Vincent's paintings as 'the work of a madman', Van Gogh admired those of Cézanne's pictures that he knew, including this one.
Here is R.S. Thomas...

Wanting to find out
if it was on the edge
of something? But the surroundings
blurred; only the way to it

clear, as it was meant
to be for the earless painter
coming with his mind in pieces
to mend it by the light of those eyes.