Что касается оправы, то эта мне подходит.

Что касается is a set expression meaning as for, regarding, or when it comes to.

So:

• Что касается оправы... = As for the frame...

Literally, касаться means to concern, to relate to, or to touch on in an abstract sense. In this expression, it introduces a topic.

This is a very common way to shift the focus of a conversation:

• Что касается цены... = As for the price...
• Что касается цвета... = As for the color...

Because касаться normally takes the genitive case.

The dictionary form is оправа, but after касаться it becomes оправы:

• оправа → nominative
• оправы → genitive singular

So:

• что касается оправы = as for the frame

This is something learners often just have to memorize with the verb/pattern:

• касаться чего? = to concern what? → genitive

The то here helps mark the main part of the sentence after the topic phrase. It is often used in structures like:

• Что касается X, то Y.

So the sentence is structured like this:

• Что касается оправы = topic: as for the frame
• то эта мне подходит = comment: this one suits me

In English, we usually do not need a separate word like то, so it may feel redundant. In Russian, it sounds natural and helps organize the sentence.

You can think of it as something like:

• As for the frame, this one suits me.

The то does not really get translated directly.

Yes, often it can.

You can say:

• Что касается оправы, эта мне подходит.

This is understandable and natural in many contexts. But то makes the topic-comment structure clearer and often sounds a bit more polished or explicit.

So both are possible, but:

• Что касается оправы, то эта мне подходит. = slightly more formal/structured
• Что касается оправы, эта мне подходит. = also fine

Because the implied noun is оправа, which is feminine.

• этот = masculine
• эта = feminine
• это = neuter

Since оправа is feminine, the demonstrative must agree with it:

• эта (оправа) = this (frame)

Russian often leaves out a noun when it is clear from context. So эта here really means:

• эта оправа = this frame
• or more naturally in English, this one

Because Russian often omits a noun when it is obvious from context.

Here, the topic has already been established:

• Что касается оправы... = As for the frame...

So in the second part, saying just эта is enough:

• эта мне подходит = this one suits me

If you wanted, you could say the full version:

• Что касается оправы, то эта оправа мне подходит.

But that sounds repetitive. Native speakers usually prefer the shorter version.

Because the verb подходить in this meaning works like to suit or to fit someone, and the person is put in the dative case.

So:

• мне = to me / for me
• подходит = suits / fits

Together:

• эта мне подходит = this one suits me / this one works for me

This is a common Russian pattern:

• Мне нравится = I like it literally It is pleasing to me
• Мне подходит = It suits me
• Мне нужно = I need literally To me it is necessary

So Russian often uses structures where English uses I as the subject.

Here подходит means suits, fits, or works for.

Depending on context, подходить can mean different things:

• to approach / come up to
• to suit
• to fit
• to be appropriate

In this sentence, it means something like:

• This frame suits me
• This frame works for me
• This frame fits me

If the context is appearance or style, suits me is often the best translation. If the context is physical fit, fits me may be better.

Because its subject is эта = this one, which is singular.

Even though English may translate it more freely, the Russian grammar is straightforward:

• эта = singular feminine
• подходит = third person singular

If the subject were plural, the verb would also be plural:

• Эти мне подходят. = These suit me.

Yes, it is normal and natural.

Russian word order is flexible, but different orders can shift emphasis.

• Эта мне подходит. = neutral, natural
• Мне эта подходит. = a bit more emphasis on to me
• Эта подходит мне. = possible, but less neutral in everyday speech

In your sentence, эта мне подходит sounds very natural because the speaker is likely choosing among several options and saying this one suits me.

Because Что касается оправы is an introductory topic phrase, and the main clause follows it.

The sentence is divided like this:

• Что касается оправы,
• то эта мне подходит.

So the comma marks the boundary between:

1. the topic introduced by что касается
2. the main statement

This punctuation is standard in Russian.

You could analyze it that way word-for-word, but that is not how natural English would express it.

A closer literal breakdown is:

• Что касается = what concerns / as concerns
• оправы = of the frame
• то = topic marker, not really translated directly
• эта = this one
• мне подходит = suits me

But the natural English translation is:

• As for the frame, this one suits me.

So yes, the literal structure helps explain the grammar, but it should not be copied into English too closely.

It is mostly neutral.

• Что касается... can sound a little more structured than just speaking very casually, but it is still common and natural.
• Эта мне подходит is perfectly normal everyday Russian.

So the whole sentence sounds like standard, natural Russian. It could appear in conversation, especially when discussing options, such as frames, clothes, colors, or styles.

A more casual alternative might be something like:

• Насчёт оправы — эта мне подходит.

But your original sentence is completely normal and correct.