ried.

8 But to return to the consideration of Colours: As an apparition of them
may be produced by motions from within, without the assistance of an
outward object, so I have observed, that 'tis sometimes possible that the
Colour that would otherwise be produced by an outward object, may be
chang'd by some motion, or new texture already produced in the Sensory, as
long as that unusual motion, or new disposition lasts; for I have divers
times try'd, that after I have through a Telescope look'd upon the Sun,
though thorow a thick, red, or blew glass, to make its splendor supportable
to the eye, the impression upon the _Retina_, would be not only so vivid,
but so permanent, that if afterwards I turned my eye towards a flame, it
would appear to mee of a Colour very differing from its usual one. And if I
did divers times successively shut and open the same eye, I should see the
adventitious Colour, (if I may so call it) changed or impair'd by degrees,
till at length (for this unusual motion of the eye would not presently
cease) the flame would appear to mee, of the same hew that it did to other
beholders; a not unlike effect I found by looking upon the Moon, when she
was near full, thorow an excellent Telescope, without colour'd Glass to
screen my eye with; But that which I desire may be taken notice of, because
we may elsewhere have occasion to reflect upon it, and because it seems not
agreeable to what Anatomists and Optical Writers deliver, touching the
relation of the two eyes to each other, is this circumstance, that though
my Right eye, with which I looked thorow the Telescope, were thus affected
by the over-strong impression of the light, yet when the flame of a Candle,
or some other bright object appear'd to me of a very unusual Colour, whilst
look'd upon with the Discompos'd Eye, or (though not so notably) with both
eyes at once; yet if I shut that Eye, and looked upon the same object with
the other, it would appear with no other than its usual Colour, though if I
again opened, and made use of the Dazled eye, the vivid adventitious Colour
would again appear. And on this occasion I must not pretermit an
Observation which may perswade us, that an over-vehement stroak upon the
Sensory, especially if it be naturally of a weak constitution, may make a
more lasting impression than one would imagine, which impression may in
some cases, as it were, mingle with, and vitiate the action of vivid
objects for a long time after.