La vista cambia con el tiempo.

In Spanish, it is very common to use the definite article with nouns when talking about things in a general sense.

So la vista here means sight / eyesight / vision as a general human ability.

• La vista cambia con el tiempo. = Sight changes over time.

Using just vista by itself would sound incomplete in this sentence.

Here, vista means sight, eyesight, or vision.

Be careful, because vista can mean different things depending on context:

• la vista = sight / eyesight
• una vista = a view
• las vistas = the views / the scenery

So in this sentence, la vista is not the view. It means the ability to see.

Because the subject is singular: la vista.

• la vista = singular
• cambia = it changes

If the subject were plural, then you would use cambian:

• Las cosas cambian con el tiempo. = Things change over time.

So the sentence agrees correctly:

• La vista cambia... = Sight changes...

Cambia is the third person singular present tense of cambiar.

The present tense forms are:

• yo cambio
• tú cambias
• él / ella / usted cambia
• nosotros cambiamos
• vosotros cambiáis
• ellos / ellas / ustedes cambian

In this sentence, la vista is treated like it, so Spanish uses cambia.

Because Spanish often uses the present tense for general facts, habits, and things that are generally true.

So:

• La vista cambia con el tiempo.

means something like:

• Sight changes over time
• Eyesight changes as time passes

This is completely normal in Spanish, just like in English:

• Water boils at 100 degrees.
• People change.
• La vista cambia...

Con el tiempo is a very common Spanish expression meaning:

• over time
• with time
• as time goes by

So this phrase is best learned as a chunk:

• con el tiempo = over time

By contrast, en el tiempo usually refers more literally to in time or within time, and it would not be the natural choice here.

It can mean both, depending on context.

• el tiempo = time
• el tiempo = weather

Here it clearly means time, because of the phrase con el tiempo.

Examples:

• No tengo tiempo. = I don’t have time.
• Hace buen tiempo. = The weather is nice.

This is a very common point of confusion for English speakers.

Yes, you could, but it is not exactly the same in tone.

• la vista is very common for sight / eyesight
• la visión can also mean vision, but it can sound a bit more formal, technical, or abstract

Also, visión can mean not only physical vision but also a vision, outlook, or way of seeing things.

So for ordinary eyesight, la vista is often the most natural choice.

No, here cambiar is not reflexive.

• La vista cambia con el tiempo. = Sight changes over time.

That simply means the subject changes.

Spanish sometimes uses cambiar and cambiarse, but they are not always the same:

• cambiar = to change / to alter / to replace
• cambiarse = to change oneself, often clothes or place in some contexts

For this sentence, plain cambiar is correct.

A simple pronunciation guide would be:

la BEES-ta KAHM-byah kon el tee-EM-poh

A few useful notes:

• v in vista is usually pronounced much like a soft b sound in Spanish
• c in cambia sounds like k
• ia in cambia glides together: KAHM-byah
• tiempo has two syllables after the initial ti sound: tee-EM-po

A more approximate IPA pronunciation is:

[la ˈβista ˈkambja kon el ˈtjempo]

Yes, but La vista cambia con el tiempo is the most neutral and natural order.

Spanish word order is fairly flexible, so you might also hear:

• Con el tiempo, la vista cambia.

This puts more emphasis on over time.

Both are correct, but the original sentence is the most straightforward.

Yes, a Spanish speaker could definitely say this. It sounds natural.

It is a normal, clear sentence meaning that eyesight changes as time passes.

Depending on context, native speakers might also say things like:

• La vista empeora con la edad. = Eyesight gets worse with age.
• Con el tiempo, la vista va cambiando. = Over time, eyesight gradually changes.

But your original sentence is perfectly good Spanish.

Both can refer to change across time, but they feel a little different.

• con el tiempo = over time / with time / as time goes by
  • very common and everyday
• a lo largo del tiempo = throughout time / over the course of time
  • a bit more formal or descriptive

So in this sentence, con el tiempo is the most natural everyday choice:

• La vista cambia con el tiempo.

It sounds simple and idiomatic.