يركز صديقي على لوحة فحص النظر ويرمش.

Because Arabic often uses verb–subject–object order, especially in straightforward narration.

So:

• يركز صديقي... = literally focuses my friend...
• very natural in Arabic

You could also say:

• صديقي يركز على لوحة فحص النظر ويرمش

That is also correct, but it gives a slightly different emphasis, with my friend more foregrounded.

يركز means he focuses / he concentrates.

A few useful points:

• It is a present/imperfect verb form.
• It is 3rd person masculine singular.
• In this sentence, it matches صديقي because my friend is singular and grammatically masculine.

In fully vocalized Arabic, it is usually:

• يُرَكِّزُ

This comes from the root ر ك ز, associated with focusing, fixing, or concentrating.

Because the ending ـي is the possessive suffix meaning my.

So:

• صديق = friend
• صديقي = my friend

This is very common in Arabic:

• كتابي = my book
• بيتي = my house
• اسمي = my name

So صديقي is not just friend; it already includes the idea of my.

Because Arabic commonly says يركز على for focus on.

So the combination is:

• يركز على شيء = he focuses on something

This is just one of those verb + preposition pairings you need to learn as a unit, because they do not always match English perfectly.

Examples:

• يركز على الدرس = he focuses on the lesson
• يركز على الهدف = he focuses on the goal

This is a noun chain called an iḍāfa construction.

It is built like this:

• لوحة = board / chart / panel
• فحص = examination / test
• النظر = vision / sight

So literally it is something like:

• chart of vision testing
• or more naturally, eye chart / vision test chart

Arabic often expresses this kind of idea by linking nouns together instead of using a word like of.

So:

• لوحة فحص النظر = the chart of the vision test

Because in an iḍāfa construction, the first noun does not take ال.

So Arabic says:

• لوحة فحص النظر

not:

• اللوحة فحص النظر

The definiteness comes from the whole chain, especially from the last definite noun:

• النظر

Since النظر is definite, the whole phrase becomes definite in meaning.

This is a very important rule in Arabic noun phrases.

Because لوحة is followed by another noun in an iḍāfa construction.

The final ة is tāʾ marbūṭa. When you stop on the word by itself, it is usually pronounced like -a:

• لوحة = lawḥa

But when it is connected grammatically to what follows, it is pronounced -at (or with its case ending):

• لوحة فحص... ≈ lawḥat faḥṣ...

This is why learners often hear a t sound in connected speech.

ويرمش means and he blinks or and he is blinking.

It breaks down as:

• و = and
• يرمش = he blinks

Arabic verbs already include the subject information, so you do not need a separate word for he here.

So Arabic can simply say:

• ويرمش = and he blinks

The subject is understood to be the same as before: my friend.

Both are in the imperfect form, which often covers what English expresses with the present tense.

Depending on context, this can mean:

• he focuses and blinks
• he is focusing and blinking
• he focuses ... and then blinks

Arabic imperfect verbs are a bit broader than English tense labels, so context decides the best translation.

In this sentence, the sense is a present action or description.

A fully vocalized version would be:

يُرَكِّزُ صَدِيقِي عَلَى لَوْحَةِ فَحْصِ النَّظَرِ وَيَرْمُشُ.

A few grammar notes:

• يُرَكِّزُ = nominative imperfect verb
• صَدِيقِي = the subject, my friend
• عَلَى = preposition on
• لَوْحَةِ = genitive after على
• فَحْصِ = also genitive, because it is in iḍāfa
• النَّظَرِ = genitive as the final noun in the iḍāfa chain
• وَيَرْمُشُ = and he blinks

In normal everyday writing, these short vowels are usually omitted.

Yes, it is understandable and natural enough, but there are other common ways to say it too.

Possible alternatives include:

• لوحة فحص البصر = vision-test chart
• لوحة اختبار النظر = eyesight test chart
• لوحة النظر = eye chart, in a shorter phrasing

So the sentence is good Arabic, but depending on context, another phrasing might also be used.

It usually means to blink.

So يرمش is specifically about the eyelids blinking. That is narrower than a more general verb like:

• يغمض عينيه = he closes his eyes

So if the intended meaning is the small repeated eye movement, يرمش is the right idea.

Yes. You could say:

صديقي يركز على لوحة فحص النظر ويرمش.

That is also grammatical.

The difference is mostly one of style and emphasis:

• يركز صديقي... = more narrative, very standard
• صديقي يركز... = puts more attention on my friend

Both are good Arabic.