|Why does my eye color change hourly? P.S. I am
|Question Date: 2005-05-13|
The quick answer is that yours eyes don't change,
but the way we see your eyes does. I said it was
quick, not quick to understand. Here's what's
happening. When we see something, we are really
seeing light that comes from some source (a lamp,
the sun, etc.) then bounces off an object and into
our own eyes. There are some great tutorials on
light and color at:
Just click on a topic and an
animation will be activated.
The angle we
observe an object from can change the apparent
color of an object. Take a glossy photograph or
magazine picture and look at it from various
angles. The picture doesn't change, but the way
we see it does. So does the light source. Look
at the ocean on different days and from different
angles (on the beach, from the pier, from the
hills) and you will see a similar
When different amounts and types of
light (fluorescent, sunlight, etc.) hit your eyes
from different angles, or we look at your eyes
from different angles, they will seem to be
different colors. When your pupil (the hole in
the middle of your eye) is more dilated (open) or
constricted (closed), the color will also seem to
change. Imagine you stretch a balloon out; the
color will lighten as the material stretches.
Dilation or constriction of your pupil will also
change light angles.
Your eyes may seem to
change more than your friends' eyes do if you have
different pigments (colors) in your iris (the
colored part of your eye).
By the time you
understand why the color of your eyes seems to
change, you will have learned a lot about both
color and how yours eyes work
The color of your eye is determined by
pigmentation of the iris cells by varying amounts
of melanin. The iris is sandwiched between the
cornea and the lens at the front of the eye, and
surrounds the pupil, which expands and contracts
to adjust the amount of light let in. There are
two areas of the iris which may vary in
pigmentation, the front and back surface.
Generally the back has about the same amount of
pigment in everyone, but the front varies a lot.
Heavy pigment on the front causes more light
absorption and browner eyes, less pigmentation
causes increased reflectance and more blue or gray
colors. The more the eye reflects, the more likely
it is that colors around you will affect the color
of your eye.
People with less-pigmented irises
tend to experience a lot of daily eye color
variation depending on the color of the light
reflecting off of the iris. Your shirt color, the
angle of the sun, the cloud cover, the presence of
water...all of these things can cause your eye
color to change more or less depending on how
heavily pigmented your eyes are. As we age, our
eyes tend to increase their melanin production,
and stress, medications, sickness, or eye problems
can also cause changes over time.
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