have
She has very little sight in her left eye.

lose
He's lost the sight of one eye.

regain
save
The surgeons battled to save her sight.

restore

deteriorate, fail, go (all esp. BrE)
I think my sight is beginning to go.

return
His sight returned by degrees.

test (BrE)
defects (BrE), problems
loss (BrE)
This disease is the main cause of sight loss among those aged 50 and over.

the/your sense of sight

catch, get, have
She suddenly caught sight of the look on her mother's face.
We will soon get our first sight of the Statue of Liberty.

keep
She kept sight of him in her mirror.

lose

gag
The movie is filled with dozens of funny sight gags.

at the sight (of)
Her knees went weak at the sight of him.

on sight
Soldiers have been ordered to shoot looters on sight (= as soon as they see them).

at first sight
He looked at first sight like a tourist.
It was love at first sight.

cannot bear the sight of sth, cannot stand the sight of sth (= hate seeing sb/sth)
I can't stand the sight of blood.

a clear sight of sth (esp. BrE)
He didn't shoot until he had a clear sight of the goal.

know sb by sight (= to recognize sb without knowing them well)
the mere sight of sb/sth, the very sight of sb/sth
The mere sight of her sitting there made his heart beat faster.

sick of the sight of sb/sth (esp. BrE)
We've shared an office for too long and we're sick of the sight of each other.

sight unseen
I bought it, sight unseen (= without seeing it).

come into
Then the towers of the castle came into sight.

disappear from, vanish from
She watched until the car disappeared from sight.

block, block out
hide (sth) from, remove sth from
I hid the papers from sight.

in sight
Keep their car in sight for as long as you can.
The end is in sight (= will happen soon). (figurative)

out of sight
He kept out of sight behind a pillar.
You'd better stay out of sight until they go.

within sight of
Her staff of 30 work in an industrial loft within sight of Logan Airport.

in full sight of sb
He tried to break into a car in full sight of a policeman.

in plain sight
They waited until the enemy was in plain sight.

be nowhere in sight
Her father was nowhere in sight.

come in sight of sb/sth
At last we came in sight of a few houses.

no end in sight
The violence continues with no end in sight.

not leave sb's sight
He won't let the children leave his sight.

sb's line of sight
She was now standing just out of his line of sight.

not let sb/sth out of your sight
Whatever you do, don't let them out of your sight!

common, familiar, regular (esp. BrE)
Tom was a pretty familiar sight around the casino.

bizarre, odd, rare, strange, unexpected, unfamiliar, unlikely (esp. BrE), unusual
amazing, awe-inspiring, awesome, beautiful, breathtaking, extraordinary, fine, impressive, inspiring, magnificent, spectacular, splendid (esp. BrE), unforgettable, wonderful
depressing, pathetic, pitiful, sad, sorry, unedifying (BrE)
He really did look a sorry sight, with his clothes covered in mud.

disturbing
ghastly, gruesome, horrible, horrific, horrifying, terrible, terrifying
welcome
Dan's face was a welcome sight.

behold, see, witness
This is a sight not often seen on concert stages in this country.
I witnessed the awful sight of children drinking dirty water from puddles.

look (BrE,informal)
You look a sight in that hat!

enjoy
Who does not enjoy the sight and sounds of birds in the country?

greet
An appalling sight greeted her.

be quite a sight
The military parade was quite a sight.

be spared the sight of sth
Thankfully, we were spared the sight of his naked body.

not a pretty sight
I'm not a pretty sight when I get out of bed in the morning.

sights and sounds
The sights and sounds of the city distracted her from her work.

famous, historic

see, take in, visit
Let's get out of the hotel and see the sights.

gun (usually gunsight)
adjustable, fixed
optical, telescopic
night, thermal, thermal-imaging
laser
front, rear

adjust, align
to align the sights on the target

in your sight
He fixed the deer in his sights and pulled the trigger.

have sb/sth in, have sb/sth within
Rossi has the defending champion in her sights in tomorrow's race.

fix, train, turn
She turned her sights on Florida's adoption laws.

lower, raise
After failing to get into college, he lowered his sights and got a job in a bar.

have your sights set on sth, set your sights on sth
She has her sights set on becoming a writer.

set your sights high, set your sights low
He says he wants to win the trophy, but I think he's setting his sights too high.