وسادة الأنف قرب العدسة.

Because this is an iḍāfa construction, often called a construct phrase.

• وسادة = pad / cushion
• الأنف = the nose

So وسادة الأنف literally means the pad of the nose, which English naturally expresses as nose pad.

Arabic often uses this noun + noun structure where English uses a compound noun:

• باب البيت = the door of the house = the house door
• لون العين = the color of the eye = eye color

So here, وسادة الأنف is the normal way to say nose pad.

That is a key rule of iḍāfa.

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun determines whether the whole phrase is definite

So:

• وسادة أنف = a nose pad / nose pad of a nose
• وسادة الأنف = the nose pad

Even without الـ on وسادة, the whole phrase becomes definite because the second noun is definite: الأنف.

Because in an iḍāfa, the second noun is grammatically genitive.

So in fully vowelled MSA, you would have:

وِسادةُ الأنفِ

• وسادةُ = nominative here
• الأنفِ = genitive because it is the second part of the iḍāfa

In normal Arabic writing, these case endings are usually not written, but they are part of the grammar.

Here قرب functions like an adverbial noun of place meaning near / close to.

So:

• قرب العدسة = near the lens

Grammatically, it behaves a bit like a noun in a construction:

• قربَ is in an adverbial/accusative role
• العدسةِ is genitive after it

In full vocalization: قُرْبَ العَدَسَةِ

For a learner, the easiest practical understanding is:

• memorize قرب + noun = near + noun

Because Arabic normally omits the present-tense to be in simple statements.

So where English says:

• The nose pad is near the lens

Arabic can simply say:

• وسادة الأنف قرب العدسة

This is a normal nominal sentence in Arabic:

• وسادة الأنف = the topic/subject
• قرب العدسة = the predicate/comment

If you wanted was or will be, then Arabic would normally use a verb:

• كانت وسادة الأنف قرب العدسة = The nose pad was near the lens

It could be understood either way, depending on context.

As a full sentence, it means:

• The nose pad is near the lens

But in real-life usage, this kind of short phrase is also very common in:

• diagrams
• product descriptions
• technical labels
• parts lists

Arabic often uses concise structures like this where English might also use a shortened label style.

A useful pronunciation is:

wisādat al-ʾanf qurb al-ʿadasa

A few important points:

• وسادة by itself is usually pronounced wisāda
• but in وسادة الأنف, the final ة is pronounced -t, because it is in an iḍāfa
  • so: wisādat al-ʾanf

Also:

• الأنف is pronounced al-ʾanf
• العدسة is pronounced al-ʿadasa in pause

So the ة:

• often sounds like -a at the end of a paused word
• but sounds like -t when followed grammatically, especially in iḍāfa or with case endings

A careful fully vowelled version would be:

وِسادةُ الأنفِ قُرْبَ العَدَسَةِ

Breakdown:

• وِسادةُ = nominative, as the subject/topic
• الأنفِ = genitive, as the second noun in the iḍāfa
• قُرْبَ = adverbial accusative
• العَدَسَةِ = genitive after قرب

In ordinary writing, these short vowels are usually omitted: وسادة الأنف قرب العدسة

Yes. That would also be correct.

For example:

• وسادة الأنف قريبة من العدسة = The nose pad is close to the lens

The difference is mostly style:

• قرب العدسة is shorter and more compact
• قريبة من العدسة sounds more like a regular full descriptive sentence

So:

• وسادة الأنف قرب العدسة = concise, label-like, efficient
• وسادة الأنف قريبة من العدسة = more explicit and conversational

Because the sentence is referring to a specific lens, not just any lens.

• العدسة = the lens
• عدسة = a lens

In technical or visual contexts, Arabic often uses the definite form when the object is already clear from the situation, such as a labeled part of glasses, a camera, or an optical device.

So قرب العدسة naturally means near the lens, with a specific lens understood from context.