עדשות מגע לא צריכות מסגרת משקפיים.

Because עדשות is a feminine plural noun, and צריך in the present tense agrees with the subject in gender and number.

The present-tense forms are:

• צריך — masculine singular
• צריכה — feminine singular
• צריכים — masculine plural
• צריכות — feminine plural

So with עדשות מגע = contact lenses, the correct form is צריכות.

Here it means need.

Hebrew צריך can mean either:

• need
• should / have to / ought to

The exact meaning depends on context.

In this sentence, because the thing following it is an object — מסגרת משקפיים — the meaning is clearly need:

• עדשות מגע לא צריכות מסגרת משקפיים
  = Contact lenses do not need eyeglass frames.

If the sentence were about what someone ought to do, then צריך might be better translated as should or has to.

Yes. עדשות מגע is a single noun phrase meaning contact lenses.

Literally, it is something like lenses of contact. This is a very common Hebrew structure called the construct state.

• עדשות = lenses
• מגע = contact

מגע stays singular because it is an abstract noun, contact, and Hebrew commonly uses the singular in this kind of phrase. English does something similar: in contact lenses, the word contact is not plural either.

The singular form is:

• עדשת מגע = contact lens

The plural is:

• עדשות מגע = contact lenses

Because את is only used before a definite direct object.

Here, מסגרת משקפיים is indefinite — it means an eyeglass frame / glasses frame, not the frame. So there is no את.

Compare:

• עדשות מגע לא צריכות מסגרת משקפיים
  = Contact lenses do not need a glasses frame.

But if you were talking about a specific frame, you would use את:

• עדשות המגע לא צריכות את מסגרת המשקפיים
  = The contact lenses do not need the eyeglass frame.

Yes. מסגרת משקפיים is also a construct-state phrase.

Literally, it means frame of glasses.

• מסגרת = frame
• משקפיים = glasses / eyeglasses

So the whole phrase means a glasses frame or an eyeglass frame.

A useful point: the head noun here is מסגרת, which is singular, so the whole phrase is singular even though משקפיים looks plural.

Because משקפיים is one of those Hebrew nouns that is normally used in a plural form for a single object, much like English glasses.

So:

• משקפיים = glasses / eyeglasses

Even when you mean one pair of glasses, Hebrew usually still uses משקפיים.

That is why מסגרת משקפיים means a glasses frame, not frames.

Because the sentence is making a general statement, not talking about specific contact lenses or a specific frame.

• עדשות מגע = contact lenses, in general
• מסגרת משקפיים = a glasses frame, in general

If you wanted to talk about specific ones, you could make them definite:

• עדשות המגע = the contact lenses
• מסגרת המשקפיים = the glasses frame

In construct phrases, the definiteness is usually shown on the second noun:

• מסגרת משקפיים = a glasses frame
• מסגרת המשקפיים = the glasses frame

It can do both.

צריך can be followed by:

1. a noun
2. an infinitive with ל־

Examples:

• אני צריך מים = I need water.
• אני צריך לישון = I need to sleep.

In your sentence, it is followed by a noun phrase:

• צריכות מסגרת משקפיים = need an eyeglass frame

So this structure is completely normal.

Because לא normally comes directly before the verb or predicate that it negates.

So:

• לא צריכות = do not need

The basic order here is:

• עדשות מגע — subject
• לא צריכות — negated predicate
• מסגרת משקפיים — object

So the sentence structure is very straightforward:

Subject + לא + need + object

The singular would be:

• עדשת מגע לא צריכה מסגרת משקפיים.

That uses צריכה, the feminine singular form, because עדשה is feminine singular.

Compare:

• עדשת מגע לא צריכה... = A contact lens does not need...
• עדשות מגע לא צריכות... = Contact lenses do not need...

A helpful pronunciation guide is:

a-da-SHOT ma-GA lo tsri-KHOT mis-GE-ret mish-ka-FA-yim

Or in a smoother transliteration:

adashot maga lo tzrikhot misgeret mishkafayim

A few pronunciation notes:

• צ sounds like ts in cats
• ח in צריכות is a throaty sound that English does not really have
• The stress is roughly on:
  • עדשׁוֹת → -shot
  • מגּע → -ga
  • צריכוֹת → -khot
  • מסגּרת → -ge-
  • משקפיים → -fa-yim

Yes, it is understandable and natural enough, especially in a context where you are contrasting contact lenses with glasses.

It says plainly that contact lenses do not require a glasses frame.

Depending on context, a speaker might also say something slightly shorter, such as:

• עדשות מגע לא צריכות מסגרת.

But your sentence is perfectly clear, and מסגרת משקפיים makes the idea extra explicit for a learner.