Analysis of Sonnet 22

Cyriac, this three years' day these eyes, though clear,
To outward view, of blemish or of spot,
Bereft of light, their seeing have forgot;
Nor to their idle orbs doth sight appear
Of sun, or moon, or star, throughout the year,
Or man, or woman. Yet I argue not
Against Heav'n's hand or will, nor bate a jot
Of heart or hope; but still bear up and steer
Right onward. What supports me, dost thou ask?
The conscience, Friend, t' have lost them overplied
In liberty's defence, my noble task,
Of which all Europe rings from side to side.
This thought might lead me through the world's vain mask
Content, though blind, had I no better guide.