Antirefleksbelegget ligger på brilleglasset.

Because Norwegian very often forms compound nouns by joining words together.

So:

• antirefleks + belegg = antirefleksbelegg
• brille + glass = brilleglass

English often writes these as separate words, like anti-reflective coating or glasses lens, but Norwegian usually prefers one combined word.

This is very normal in Norwegian, and English speakers often need time to get used to it.

The ending -et is the definite article for many neuter nouns.

So:

• et belegg = a coating
• belegget = the coating

and

• et glass = a glass / a lens
• glasset = the glass / the lens

In this sentence, both nouns are in the definite singular form.

In Norwegian, the is usually added to the end of the noun instead of being a separate word before it.

So instead of saying something like the coating, Norwegian says:

• belegget = the coating

and instead of the lens:

• glasset = the lens

This is one of the biggest differences from English noun structure.

Norwegian often uses verbs like ligge, stå, and sitte where English would simply use be.

Here, ligger literally means lies, but in natural English the sentence is usually translated with is.

Why ligger here?

Because the coating is understood as something that lies on or rests on the surface of the lens.

So:

• Antirefleksbelegget ligger på brilleglasset.
  literally: The anti-reflection coating lies on the lens.
• natural English: The anti-reflective coating is on the lens.

You might hear er på in some contexts, but ligger på sounds more physical and natural here.

På usually means on.

It is used here because the coating is understood as being on the surface of the lens.

So:

• på brilleglasset = on the lens

That matches English fairly closely in this sentence.

Brilleglass means a spectacle lens / eyeglass lens.

Even though glass often means glass as a material or a drinking glass, in compounds it can also mean lens, especially in words connected to glasses.

So:

• brille = glasses
• brilleglass = the lens of a pair of glasses

In the sentence, brilleglasset is the lens.

In Norwegian compounds, the last element usually tells you what kind of thing the whole word is.

For example:

• antirefleksbelegg is a kind of belegg
• brilleglass is a kind of glass

The earlier part just gives extra information.

This is also why the gender and definite ending are determined by the last part:

• belegg is neuter, so belegget
• glass is neuter, so glasset

Yes. The normal neutral order is:

• Antirefleksbelegget ligger på brilleglasset.

But Norwegian can move parts around for emphasis. For example:

• På brilleglasset ligger antirefleksbelegget.

That version is grammatical, but it sounds more marked or literary, because it emphasizes on the lens.

For a learner, the original word order is the safest and most natural.

If you wanted an indefinite version, you could say:

• Et antirefleksbelegg ligger på et brilleglass.

That means something like An anti-reflective coating is on a lens.

But in real use, the definite form often sounds more natural here, especially if you are talking about a specific coating and a specific lens.

Yes. Brilleglasset is singular.

The sentence is talking about one lens. If you wanted to talk about both lenses, you would use a plural form instead.

So this sentence does not mean the whole pair of glasses. It specifically refers to the lens.

Not exactly in the usual adjective sense.

In antirefleksbelegg, antirefleks- is the first part of a compound noun. It functions like a descriptive element inside the compound.

So instead of saying something like a coating that reduces reflection, Norwegian packs that idea into one noun:

• antirefleksbelegg

This kind of compact noun-building is extremely common in Norwegian.