Euphrasy: "The Land Of Life To Look At And Explore"

I had never seen the word "euphrasy" until I came across it in this poem by Siegfried Sassoon:

                    Euphrasy

The large untidy February skies --
Some cheerful starlings screeling on a tree --
West wind and low-shot sunlight in my eyes --
   Is this decline for me?

The feel of winter finishing once more --
Sense of the present as a tale half told --
The land of life to look at and explore --
   Is this, then, to grow old?

Common Chords (1950).  Sassoon wrote the poem in 1949, at the age of 63.

                                      Stanley Roy Badmin, "February"

According to the Oxford English Dictionary, "euphrasy" is "a plant, Euphrasia officinalis, formerly held in high repute for its medicinal virtues in the treatment of diseases of the eye."  "Eye-bright" is "the popular name of the plant."  The OED states that "euphrasy" may be used figuratively, and provides an example from Frederick Faber's Bethlehem (1865):  "Eyes which have been touched with the special euphrasy of heaven."  A few years after encountering Sassoon's poem, I discovered that Walter de la Mare, who was a friend of Sassoon's, also wrote a poem titled "Euphrasy."  It appears in de la Mare's 1938 collection, Memory and Other Poems.

                                                Euphrasy/Eye-Bright