【医】 色盲

[ noun ]
genetic inability to distinguish differences in hue
<noun.state>

Blindness \Blind"ness\, n.
State or condition of being blind, literally or figuratively.
--Darwin.

{Color blindness}, inability to distinguish certain color.
See {Daltonism}.


Color \Col"or\ (k[u^]l"[~e]r), n. [Written also {colour}.] [OF.
color, colur, colour, F. couleur, L. color; prob. akin to
celare to conceal (the color taken as that which covers). See
{Helmet}.]
1. A property depending on the relations of light to the eye,
by which individual and specific differences in the hues
and tints of objects are apprehended in vision; as, gay
colors; sad colors, etc.

Note: The sensation of color depends upon a peculiar function
of the retina or optic nerve, in consequence of which
rays of light produce different effects according to
the length of their waves or undulations, waves of a
certain length producing the sensation of red, shorter
waves green, and those still shorter blue, etc. White,
or ordinary, light consists of waves of various lengths
so blended as to produce no effect of color, and the
color of objects depends upon their power to absorb or
reflect a greater or less proportion of the rays which
fall upon them.

2. Any hue distinguished from white or black.

3. The hue or color characteristic of good health and
spirits; ruddy complexion.

Give color to my pale cheek. --Shak.

4. That which is used to give color; a paint; a pigment; as,
oil colors or water colors.

5. That which covers or hides the real character of anything;
semblance; excuse; disguise; appearance.

They had let down the boat into the sea, under color
as though they would have cast anchors out of the
foreship. --Acts xxvii.
30.

That he should die is worthy policy;
But yet we want a color for his death. --Shak.

6. Shade or variety of character; kind; species.

Boys and women are for the most part cattle of this
color. --Shak.

7. A distinguishing badge, as a flag or similar symbol
(usually in the plural); as, the colors or color of a ship
or regiment; the colors of a race horse (that is, of the
cap and jacket worn by the jockey).

In the United States each regiment of infantry and
artillery has two colors, one national and one
regimental. --Farrow.

8. (Law) An apparent right; as where the defendant in
trespass gave to the plaintiff an appearance of title, by
stating his title specially, thus removing the cause from
the jury to the court. --Blackstone.

Note: Color is express when it is averred in the pleading,
and implied when it is implied in the pleading.

{Body color}. See under {Body}.

{Color blindness}, total or partial inability to distinguish
or recognize colors. See {Daltonism}.

{Complementary color}, one of two colors so related to each
other that when blended together they produce white light;
-- so called because each color makes up to the other what
it lacks to make it white. Artificial or pigment colors,
when mixed, produce effects differing from those of the
primary colors, in consequence of partial absorption.

{Of color} (as persons, races, etc.), not of the white race;
-- commonly meaning, esp. in the United States, of negro
blood, pure or mixed.

{Primary colors}, those developed from the solar beam by the
prism, viz., red, orange, yellow, green, blue, indigo, and
violet, which are reduced by some authors to three, --
red, green, and violet-blue. These three are sometimes
called {fundamental colors}.

{Subjective color} or {Accidental color}, a false or spurious
color seen in some instances, owing to the persistence of
the luminous impression upon the retina, and a gradual
change of its character, as where a wheel perfectly white,
and with a circumference regularly subdivided, is made to
revolve rapidly over a dark object, the teeth of the wheel
appear to the eye of different shades of color varying
with the rapidity of rotation. See {Accidental colors},
under {Accidental}.