When we see well, we do not think about our eyes very often.
When
we
see
well
,
we
do
not
think
about
our
eyes
very
often
.
It is only when we cannot see perfectly that we realize how important our eyes are.
It
is
only
when
we
can
not
see
perfectly
that
we
realize
how
important
our
eyes
are
.
People who are near-sighted can only see things that are very close to their eyes.
People
who
are
near-sighted
can
only
see
things
that
are
very
close
to
their
eyes
.
Everything else seems blurry (unclear).
Everything
else
seems
blurry
(
unclear
)
.
Many people who do a lot of work, such as writing, reading and sewing become near--sighted.
Many
people
who
do
a
lot
of
work
,
such
as
writing
,
reading
and
sewing
become
near
--
sighted
.
People who are far-sighted suffer from just the opposite problem.
People
who
are
far-sighted
suffer
from
just
the
opposite
problem
.
They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm's length.
They
can
see
things
that
are
far
away
,
but
they
have
difficulty
in
reading
a
book
unless
they
hold
it
at
arm
's
length
.
If they want to do much reading, they must get glasses, too.
If
they
want
to
do
much
reading
,
they
must
get
glasses
,
too
.
Other people do not see clearly because their eyes are not exactly the right shape.
Other
people
do
not
see
clearly
because
their
eyes
are
not
exactly
the
right
shape
.
They have what is called astigmatism.
They
have
what
is
called
astigmatism
.
This, too, can be corrected by glasses.
This
,
too
,
can
be
corrected
by
glasses
.
Some people's eyes become cloudy because of cataracts.
Some
people
's
eyes
become
cloudy
because
of
cataracts
.
Long ago these people often became blind.
Long
ago
these
people
often
became
blind
.
Now, however, it is possible to operate on the cataracts and remove them.
Now
,
however
,
it
is
possible
to
operate
on
the
cataracts
and
remove
them
.
Having two good eyes is important for judging distances.
Having
two
good
eyes
is
important
for
judging
distances
.
Each eye sees things from a slightly different angle.
Each
eye
sees
things
from
a
slightly
different
angle
.
To prove this to yourself, look at an object out of one eye; then look at the same object out of your other eye.
To
prove
this
to
yourself
,
look
at
an
object
out
of
one
eye
;
then
look
at
the
same
object
out
of
your
other
eye
.
You will find the object's relation to the background and other things around it has changed.
You
will
find
the
object
's
relation
to
the
background
and
other
things
around
it
has
changed
.
The difference between these two different eye views helps us to judge how far away an object is.
The
difference
between
these
two
different
eye
views
helps
us
to
judge
how
far
away
an
object
is
.
People who have only one eye cannot judge distance as people with two eyes.
People
who
have
only
one
eye
can
not
judge
distance
as
people
with
two
eyes
.
When we see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we realize how important our eyes are.  People who are near-sighted can only see things that are very close to their eyes. Everything else seems blurry (unclear). Many people who do a lot of work, such as writing, reading and sewing become near--sighted.  People who are far-sighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm's length. If they want to do much reading, they must get glasses, too.  Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism. This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts. Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.  Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle. To prove this to yourself, look at an object out of one eye; then look at the same object out of your other eye. You will find the object's relation to the background and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.