(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (PRP we)) (VP (VBP see) (ADVP (UH well))))) (, ,) (NP (PRP we)) (VP (VBP do) (RB not) (VP (VB think) (PP (IN about) (NP (PRP$ our) (NNS eyes))) (ADVP (RB very) (RB often)))) (. .)))
When we see well, we do not think about our eyes very often.
advmod
PronType=Int
when
When
ADV
WRB
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
advcl
Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin
see
see
VERB
VBP
discourse
well
well
INTJ
UH
punct
,
,
PUNCT
,
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
aux
Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin
do
do
AUX
VBP
advmod
not
not
PART
RB
root
VerbForm=Inf
think
think
VERB
VB
case
about
about
ADP
IN
nmod:poss
Case=Gen|Number=Plur|Person=1|Poss=Yes|PronType=Prs
our
our
PRON
PRP$
obl
Number=Plur
eye
eyes
NOUN
NNS
advmod
very
very
ADV
RB
advmod
Degree=Pos
often
often
ADV
RB
punct
.
.
PUNCT
.
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADVP (RB only)) (SBAR (WHADVP (WRB when)) (S (NP (PRP we)) (VP (MD can) (RB not) (VP (VB see) (ADVP (RB perfectly)) (SBAR (IN that) (S (NP (PRP we)) (VP (VBP realize) (SBAR (WHADJP (WRB how) (JJ important)) (S (NP (PRP$ our) (NNS eyes)) (VP (VBP are)))))))))))) (. .)))
It is only when we cannot see perfectly that we realize how important our eyes are.
nsubj:outer
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
It
PRON
PRP
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
advmod
only
only
ADV
RB
advmod
PronType=Int
when
when
ADV
WRB
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
advmod
not
not
PART
RB
root
VerbForm=Inf
see
see
VERB
VB
advmod
perfectly
perfectly
ADV
RB
mark
that
that
SCONJ
IN
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
ccomp
Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin
realize
realize
VERB
VBP
advmod
PronType=Int
how
how
ADV
WRB
ccomp
Degree=Pos
important
important
ADJ
JJ
nmod:poss
Case=Gen|Number=Plur|Person=1|Poss=Yes|PronType=Prs
our
our
PRON
PRP$
nsubj
Number=Plur
eye
eyes
NOUN
NNS
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (NP (NNS People)) (SBAR (WHNP (WP who)) (S (VP (VBP are) (ADJP (JJ near-sighted)))))) (VP (MD can) (ADVP (RB only)) (VP (VB see) (NP (NP (NNS things)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (ADJP (RB very) (JJ close) (PP (IN to) (NP (PRP$ their) (NNS eyes)))))))))) (. .)))
People who are near-sighted can only see things that are very close to their eyes.
nsubj
Number=Plur
person
People
NOUN
NNS
nsubj
PronType=Rel
who
who
PRON
WP
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
acl:relcl
Degree=Pos
near-sighted
near-sighted
ADJ
JJ
aux
VerbForm=Fin
can
can
AUX
MD
advmod
only
only
ADV
RB
root
VerbForm=Inf
see
see
VERB
VB
obj
Number=Plur
thing
things
NOUN
NNS
nsubj
PronType=Rel
that
that
PRON
WDT
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
advmod
very
very
ADV
RB
acl:relcl
Degree=Pos
close
close
ADJ
JJ
case
to
to
ADP
IN
nmod:poss
Case=Gen|Number=Plur|Person=3|Poss=Yes|PronType=Prs
their
their
PRON
PRP$
obl
Number=Plur
eye
eyes
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (NN Everything)) (ADJP (JJ else))) (VP (VBZ seems) (S (ADJP (JJ blurry))) (-LRB- -LRB-) (ADJP (JJ unclear)) (-RRB- -RRB-)) (. .)))
Everything else seems blurry (unclear).
nsubj
Number=Sing|PronType=Tot
everything
Everything
PRON
NN
amod
Degree=Pos
else
else
ADJ
JJ
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
seem
seems
VERB
VBZ
xcomp
Degree=Pos
blurry
blurry
ADJ
JJ
punct
(
(
PUNCT
-LRB-
conj
Degree=Pos
unclear
unclear
ADJ
JJ
punct
)
)
PUNCT
-RRB-
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (JJ Many) (NNS people)) (SBAR (WHNP (WP who)) (S (VP (VBP do) (NP (NP (NP (DT a) (NN lot)) (PP (IN of) (NP (NN work)))) (, ,) (PP (JJ such) (IN as) (NP (NN writing) (, ,) (NN reading) (CC and) (NN sewing)))))))) (VP (VB become) (ADVP (RB near)) (, --) (VP (VBN sighted))) (. .)))
Many people who do a lot of work, such as writing, reading and sewing become near--sighted.
amod
Degree=Pos
many
Many
ADJ
JJ
nsubj:pass
Number=Plur
person
people
NOUN
NNS
nsubj
PronType=Rel
who
who
PRON
WP
acl:relcl
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
do
do
VERB
VBP
det
Definite=Ind|PronType=Art
a
a
DET
DT
obj
Number=Sing
lot
lot
NOUN
NN
case
of
of
ADP
IN
nmod
Number=Sing
work
work
NOUN
NN
punct
,
,
PUNCT
,
case
Degree=Pos
such
such
ADJ
JJ
fixed
as
as
ADP
IN
nmod
Number=Sing
writing
writing
NOUN
NN
punct
,
,
PUNCT
,
conj
Number=Sing
reading
reading
NOUN
NN
cc
and
and
CCONJ
CC
conj
Number=Sing
sewing
sewing
NOUN
NN
root
VerbForm=Inf
become
become
VERB
VB
xcomp
near
near
ADV
RB
punct
--
--
PUNCT
,
xcomp
Tense=Past|VerbForm=Part
sight
sighted
VERB
VBN
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (NP (NNS People)) (SBAR (WHNP (WP who)) (S (VP (VBP are) (ADJP (JJ far-sighted)))))) (VP (VBP suffer) (PP (IN from) (NP (RB just) (DT the) (JJ opposite) (NN problem)))) (. .)))
People who are far-sighted suffer from just the opposite problem.
nsubj
Number=Plur
person
People
NOUN
NNS
nsubj
PronType=Rel
who
who
PRON
WP
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
acl:relcl
Degree=Pos
far-sighted
far-sighted
ADJ
JJ
root
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
suffer
suffer
VERB
VBP
case
from
from
ADP
IN
advmod
just
just
ADV
RB
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
opposite
opposite
ADJ
JJ
obl
Number=Sing
problem
problem
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (S (NP (PRP They)) (VP (MD can) (VP (VB see) (NP (NP (NNS things)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (ADVP (RB far) (RB away))))))))) (, ,) (CC but) (S (NP (PRP they)) (VP (VBP have) (NP (NN difficulty)) (PP (IN in) (S (VP (VBG reading) (NP (DT a) (NN book))))) (SBAR (IN unless) (S (NP (PRP they)) (VP (VBP hold) (NP (PRP it)) (PP (IN at) (NP (NP (NN arm) (POS 's)) (NN 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.
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
They
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
root
VerbForm=Inf
see
see
VERB
VB
obj
Number=Plur
thing
things
NOUN
NNS
nsubj
PronType=Rel
that
that
PRON
WDT
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
advmod
Degree=Pos
far
far
ADV
RB
acl:relcl
away
away
ADV
RB
punct
,
,
PUNCT
,
cc
but
but
CCONJ
CC
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
conj
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
VERB
VBP
obj
Number=Sing
difficulty
difficulty
NOUN
NN
mark
in
in
SCONJ
IN
acl
VerbForm=Ger
read
reading
VERB
VBG
det
Definite=Ind|PronType=Art
a
a
DET
DT
obj
Number=Sing
book
book
NOUN
NN
mark
unless
unless
SCONJ
IN
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
advcl
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
hold
hold
VERB
VBP
obj
Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
case
at
at
ADP
IN
nmod:poss
Number=Sing
arm
arm
NOUN
NN
case
's
's
PART
POS
obl
Number=Sing
length
length
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (SBAR (IN If) (S (NP (PRP they)) (VP (VBP want) (S (VP (TO to) (VP (VB do) (NP (JJ much) (NN reading)))))))) (, ,) (NP (PRP they)) (VP (MD must) (VP (VB get) (NP (NNS glasses)) (, ,) (ADVP (RB too)))) (. .)))
If they want to do much reading, they must get glasses, too.
mark
if
If
SCONJ
IN
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
advcl
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
want
want
VERB
VBP
mark
to
to
PART
TO
xcomp
VerbForm=Inf
do
do
VERB
VB
amod
Degree=Pos
much
much
ADJ
JJ
obj
Number=Sing
reading
reading
NOUN
NN
punct
,
,
PUNCT
,
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
aux
VerbForm=Fin
must
must
AUX
MD
root
VerbForm=Inf
get
get
VERB
VB
obj
Number=Plur
glasses
glasses
NOUN
NNS
punct
,
,
PUNCT
,
advmod
too
too
ADV
RB
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (JJ Other) (NNS people)) (VP (VBP do) (RB not) (VP (VB see) (ADVP (RB clearly)) (SBAR (IN because) (S (NP (PRP$ their) (NNS eyes)) (VP (VBP are) (RB not) (ADVP (RB exactly)) (NP (DT the) (JJ right) (NN shape))))))) (. .)))
Other people do not see clearly because their eyes are not exactly the right shape.
amod
Degree=Pos
other
Other
ADJ
JJ
nsubj
Number=Plur
person
people
NOUN
NNS
aux
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
do
do
AUX
VBP
advmod
not
not
PART
RB
root
VerbForm=Inf
see
see
VERB
VB
advmod
clearly
clearly
ADV
RB
mark
because
because
SCONJ
IN
nmod:poss
Case=Gen|Number=Plur|Person=3|Poss=Yes|PronType=Prs
their
their
PRON
PRP$
nsubj
Number=Plur
eye
eyes
NOUN
NNS
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
advmod
not
not
PART
RB
advmod
exactly
exactly
ADV
RB
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
right
right
ADJ
JJ
advcl
Number=Sing
shape
shape
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (PRP They)) (VP (VBP have) (SBAR (WHNP (WP what)) (S (VP (VBZ is) (VP (VBN called) (S (NP (NN astigmatism)))))))) (. .)))
They have what is called astigmatism.
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
They
PRON
PRP
root
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
VERB
VBP
obj
PronType=Rel
what
what
PRON
WP
aux:pass
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
acl:relcl
Tense=Past|VerbForm=Part|Voice=Pass
call
called
VERB
VBN
xcomp
Number=Sing
astigmatism
astigmatism
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (DT This)) (, ,) (ADVP (RB too)) (, ,) (VP (MD can) (VP (VB be) (VP (VBN corrected) (PP (IN by) (NP (NNS glasses)))))) (. .)))
This, too, can be corrected by glasses.
nsubj:pass
Number=Sing|PronType=Dem
this
This
PRON
DT
punct
,
,
PUNCT
,
advmod
too
too
ADV
RB
punct
,
,
PUNCT
,
aux
VerbForm=Fin
can
can
AUX
MD
aux:pass
VerbForm=Inf
be
be
AUX
VB
root
Tense=Past|VerbForm=Part|Voice=Pass
correct
corrected
VERB
VBN
case
by
by
ADP
IN
obl
Number=Plur
glasses
glasses
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (DT Some) (NNS people) (POS 's)) (NNS eyes)) (VP (VBP become) (ADJP (JJ cloudy)) (PP (IN because) (IN of) (NP (NNS cataracts)))) (. .)))
Some people's eyes become cloudy because of cataracts.
det
some
Some
DET
DT
nmod:poss
Number=Plur
person
people
NOUN
NNS
case
's
's
PART
POS
nsubj
Number=Plur
eye
eyes
NOUN
NNS
root
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
become
become
VERB
VBP
xcomp
Degree=Pos
cloudy
cloudy
ADJ
JJ
case
because
because
ADP
IN
fixed
of
of
ADP
IN
obl
Number=Plur
cataract
cataracts
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (ADVP (RB Long) (RB ago)) (NP (DT these) (NNS people)) (ADVP (RB often)) (VP (VBD became) (ADJP (JJ blind))) (. .)))
Long ago these people often became blind.
advmod
Degree=Pos
long
Long
ADV
RB
advmod
ago
ago
ADV
RB
det
Number=Plur|PronType=Dem
this
these
DET
DT
nsubj
Number=Plur
person
people
NOUN
NNS
advmod
often
often
ADV
RB
root
Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin
become
became
VERB
VBD
xcomp
Degree=Pos
blind
blind
ADJ
JJ
punct
.
.
PUNCT
.
(ROOT (S (ADVP (RB Now)) (, ,) (ADVP (RB however)) (, ,) (NP (NP (PRP it))) (VP (VBZ is) (ADJP (JJ possible)) (S (VP (TO to) (VP (VP (VB operate) (PP (IN on) (NP (DT the) (NNS cataracts)))) (CC and) (VP (VB remove) (NP (PRP them))))))) (. .)))
Now, however, it is possible to operate on the cataracts and remove them.
advmod
now
Now
ADV
RB
punct
,
,
PUNCT
,
advmod
however
however
ADV
RB
punct
,
,
PUNCT
,
expl
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Degree=Pos
possible
possible
ADJ
JJ
mark
to
to
PART
TO
csubj
VerbForm=Inf
operate
operate
VERB
VB
case
on
on
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Plur
cataract
cataracts
NOUN
NNS
cc
and
and
CCONJ
CC
conj
VerbForm=Inf
remove
remove
VERB
VB
obj
Case=Acc|Number=Plur|Person=3|PronType=Prs
they
them
PRON
PRP
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (S (VP (VBG Having) (NP (CD two) (JJ good) (NNS eyes)))) (VP (VBZ is) (ADJP (JJ important)) (PP (IN for) (NP (NN judging) (NNS distances)))) (. .)))
Having two good eyes is important for judging distances.
csubj
VerbForm=Ger
have
Having
VERB
VBG
nummod
NumForm=Word|NumType=Card
two
two
NUM
CD
amod
Degree=Pos
good
good
ADJ
JJ
obj
Number=Plur
eye
eyes
NOUN
NNS
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Degree=Pos
important
important
ADJ
JJ
case
for
for
ADP
IN
amod
Number=Sing
judge
judging
NOUN
NN
obl
Number=Plur
distance
distances
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (NP (DT Each) (NN eye)) (VP (VBZ sees) (NP (NNS things)) (PP (IN from) (NP (DT a) (ADJP (RB slightly) (JJ different)) (NN angle)))) (. .)))
Each eye sees things from a slightly different angle.
det
each
Each
DET
DT
nsubj
Number=Sing
eye
eye
NOUN
NN
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
see
sees
VERB
VBZ
obj
Number=Plur
thing
things
NOUN
NNS
case
from
from
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
advmod
slightly
slightly
ADV
RB
amod
Degree=Pos
different
different
ADJ
JJ
obl
Number=Sing
angle
angle
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (S (VP (TO To) (VP (VB prove) (NP (DT this)) (PP (IN to) (NP (PRP yourself)))))) (, ,) (VP (VP (VB look) (PP (IN at) (NP (DT an) (NN object))) (PP (IN out) (PP (IN of) (NP (CD one) (NN eye))))) (: ;) (RB then) (VP (VB look) (PP (IN at) (NP (DT the) (JJ same) (NN object))) (PP (IN out) (PP (IN of) (NP (PRP$ your) (JJ other) (NN 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.
mark
to
To
PART
TO
advcl
VerbForm=Inf
prove
prove
VERB
VB
obj
Number=Sing|PronType=Dem
this
this
PRON
DT
case
to
to
ADP
IN
obl
Case=Acc|Number=Sing|Person=2|PronType=Prs|Reflex=Yes
yourself
yourself
PRON
PRP
punct
,
,
PUNCT
,
root
Mood=Imp|VerbForm=Fin
look
look
VERB
VB
case
at
at
ADP
IN
det
Definite=Ind|PronType=Art
a
an
DET
DT
obl
Number=Sing
object
object
NOUN
NN
case
out
out
ADP
IN
fixed
of
of
ADP
IN
nummod
NumForm=Word|NumType=Card
one
one
NUM
CD
obl
Number=Sing
eye
eye
NOUN
NN
punct
;
;
PUNCT
:
advmod
PronType=Dem
then
then
ADV
RB
parataxis
Mood=Imp|VerbForm=Fin
look
look
VERB
VB
case
at
at
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
same
same
ADJ
JJ
obl
Number=Sing
object
object
NOUN
NN
case
out
out
ADP
IN
fixed
of
of
ADP
IN
nmod:poss
Case=Gen|Person=2|Poss=Yes|PronType=Prs
your
your
PRON
PRP$
amod
Degree=Pos
other
other
ADJ
JJ
obl
Number=Sing
eye
eye
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (PRP You)) (VP (MD will) (VP (VB find) (SBAR (S (NP (NP (NP (DT the) (NN object) (POS 's)) (NN relation)) (PP (IN to) (NP (NP (DT the) (NN background)) (CC and) (NP (NP (JJ other) (NNS things)) (PP (IN around) (NP (PRP it))))))) (VP (VBZ has) (VP (VBN changed))))))) (. .)))
You will find the object's relation to the background and other things around it has changed.
nsubj
Case=Nom|Person=2|PronType=Prs
you
You
PRON
PRP
aux
VerbForm=Fin
will
will
AUX
MD
root
VerbForm=Inf
find
find
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod:poss
Number=Sing
object
object
NOUN
NN
case
's
's
PART
POS
obj
Number=Sing
relation
relation
NOUN
NN
case
to
to
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
background
background
NOUN
NN
cc
and
and
CCONJ
CC
amod
Degree=Pos
other
other
ADJ
JJ
nsubj
Number=Plur
thing
things
NOUN
NNS
case
around
around
ADP
IN
nmod
Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
have
has
AUX
VBZ
conj
Tense=Past|VerbForm=Part
change
changed
VERB
VBN
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (DT The) (NN difference)) (PP (IN between) (NP (DT these) (CD two) (JJ different) (NN eye) (NNS views)))) (VP (VBZ helps) (NP (PRP us)) (S (VP (TO to) (VP (VB judge) (SBAR (WHADVP (WRB how) (RB far) (RB away)) (S (NP (DT an) (NN object)) (VP (VBZ is)))))))) (. .)))
The difference between these two different eye views helps us to judge how far away an object is.
det
Definite=Def|PronType=Art
the
The
DET
DT
nsubj
Number=Sing
difference
difference
NOUN
NN
case
between
between
ADP
IN
det
Number=Plur|PronType=Dem
this
these
DET
DT
nummod
NumForm=Word|NumType=Card
two
two
NUM
CD
amod
Degree=Pos
different
different
ADJ
JJ
compound
Number=Sing
eye
eye
NOUN
NN
nmod
Number=Plur
view
views
NOUN
NNS
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
help
helps
VERB
VBZ
obj
Case=Acc|Number=Plur|Person=1|PronType=Prs
we
us
PRON
PRP
mark
to
to
PART
TO
xcomp
VerbForm=Inf
judge
judge
VERB
VB
advmod
PronType=Int
how
how
ADV
WRB
advmod
Degree=Pos
far
far
ADV
RB
ccomp
away
away
ADV
RB
det
Definite=Ind|PronType=Art
a
an
DET
DT
nsubj
Number=Sing
object
object
NOUN
NN
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (NNS People)) (SBAR (WHNP (WP who)) (S (VP (VBP have) (NP (QP (RB only) (CD one)) (NN eye)))))) (VP (MD can) (RB not) (VP (VB judge) (NP (NN distance)) (PP (IN as) (NP (NP (NNS people)) (PP (IN with) (NP (CD two) (NNS eyes))))))) (. .)))
People who have only one eye cannot judge distance as people with two eyes.
nsubj
Number=Plur
person
People
NOUN
NNS
nsubj
PronType=Rel
who
who
PRON
WP
acl:relcl
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
VERB
VBP
advmod
only
only
ADV
RB
nummod
NumForm=Word|NumType=Card
one
one
NUM
CD
obj
Number=Sing
eye
eye
NOUN
NN
aux
VerbForm=Fin
can
can
AUX
MD
advmod
not
not
PART
RB
root
VerbForm=Inf
judge
judge
VERB
VB
obj
Number=Sing
distance
distance
NOUN
NN
case
as
as
ADP
IN
obl
Number=Plur
person
people
NOUN
NNS
case
with
with
ADP
IN
nummod
NumForm=Word|NumType=Card
two
two
NUM
CD
nmod
Number=Plur
eye
eyes
NOUN
NNS
punct
.
.
PUNCT
.
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.