אני משתמשת בעדשות מגע בלי ששדה הראייה שלי נעשה צר.

משתמשת is the feminine singular present-tense form, so it tells you the speaker is female.

• אני משתמשת = I use / I am using, said by a woman
• אני משתמש = I use / I am using, said by a man

In Hebrew present tense, the verb agrees with gender and number.

It can mean either one, depending on context.

Hebrew present tense often covers both:

• a general/habitual meaning: I use
• a current meaning: I am using

In this sentence, I use is probably the more natural interpretation.

Not always, but here it is useful.

In Hebrew present tense, forms like משתמשת show gender and number, but not clearly person. So משתמשת by itself could mean:

• I use
• you use, if speaking to one woman
• she uses

Adding אני makes it clear that the meaning is I.

Because the verb להשתמש means to use, and it normally takes the preposition ב־, roughly like to use with / to make use of.

So Hebrew says:

• להשתמש בעדשות מגע = to use contact lenses

This is just the standard pattern:

• אני משתמשת בעט = I use a pen
• הוא משתמש במחשב = he uses a computer

So even though English says simply use contact lenses, Hebrew requires ב־ after להשתמש.

Literally, it is something like contact lenses or more word-for-word touch lenses.

• עדשה = lens
• עדשות = lenses
• מגע = contact / touch

So:

• עדשת מגע = contact lens
• עדשות מגע = contact lenses

This is the normal Hebrew expression for contact lenses.

בלי ש... means without ... happening or without the fact that ...

It is used when בלי is followed by a whole clause, not just a noun.

Compare:

• בלי עדשות מגע = without contact lenses
  here בלי is followed by a noun
• בלי ששדה הראייה שלי נעשה צר = without my field of vision becoming narrow
  here בלי is followed by a full clause

So בלי ש... is a very common way to say without [someone/something] doing / becoming ...

Because this is really two separate parts:

• בלי ש = without that / without ...-ing
• שדה = field

When written together, they become:

• בלי ששדה

So one ש belongs to the connector ש־, and the second ש is the first letter of שדה.

This is a construct chain in Hebrew, a very common noun pattern.

• שדה = field
• ראייה = vision / sight
• שדה הראייה = field of vision

In Hebrew, this kind of phrase is built as:

• first noun + second noun

The first noun becomes the thing being specified, and the second noun tells you what kind of field it is.

A key point: the definite article often appears only on the second noun:

• שדה הראייה = the field of vision / the visual field

That is normal Hebrew structure.

Because שלי modifies the whole phrase, not just the last word by itself.

So:

• שדה הראייה שלי = my field of vision

In Hebrew, when you have a construct phrase like שדה הראייה, a possessive such as שלי usually comes after the entire phrase.

Not:

• שדה שלי הראייה — incorrect

But:

• שדה הראייה שלי — correct

Here נעשה is a present-tense form, not past.

In this sentence, נעשה צר means:

• becomes narrow
• gets narrow

It agrees with שדה, which is masculine singular, so the form is:

• נעשה = masculine singular present

A roughly similar idea in more everyday English would be:

• without my field of vision getting narrower

Because צר agrees with שדה, not with the speaker.

• שדה is masculine singular
• so the adjective must also be masculine singular: צר

Even though the speaker is female, that does not affect this adjective. The adjective describes the field of vision, not I.

So:

• שדה ... נעשה צר = the field becomes narrow

If the noun were feminine singular, then you would use צרה.

Yes. ראייה can mean vision, sight, or eyesight, depending on context.

In שדה הראייה, it is best understood as:

• field of vision
• or visual field

So this is a fairly technical or medical-style expression, but it is perfectly understandable Hebrew.