Mi hermano es miope.

Because miope describes a lasting characteristic or condition of the person, not a temporary state or location.

• ser
  • adjective is commonly used for inherent or defining traits:
    
    • Mi hermano es alto. = My brother is tall.
    • Mi hermano es miope. = My brother is short-sighted / nearsighted.
• estar is more often used for temporary states, conditions, or location.

So Mi hermano es miope is the natural choice.

In this sentence, miope is an adjective meaning short-sighted / nearsighted.

It can also sometimes be used as a noun in context, but here it is clearly functioning as an adjective after es.

Examples:

• Ella es miope. = She is nearsighted.
• Soy miope. = I am nearsighted.

In modern standard Spanish, you normally use a possessive adjective like mi directly before the noun:

• mi hermano = my brother

You do not usually say el mi hermano in standard modern Spanish. That sounds archaic or dialectal.

So:

• mi hermano ✅
• el mi hermano ❌

Spanish often does not use an indefinite article where English does.

English says:

• My brother is a doctor
• My brother is a brother would be odd, but English often includes a before professions or classifications

In Spanish, after ser, many nouns and adjectives appear without un/una when describing what someone is.

With adjectives like miope, no article is needed:

• Mi hermano es miope.

No. Miope has the same form for masculine and feminine.

So you say:

• Mi hermano es miope.
• Mi hermana es miope.

This is common with many Spanish adjectives ending in -e.

Yes. In the plural, it becomes miopes.

Examples:

• Mi hermano es miope. = My brother is nearsighted.
• Mis hermanos son miopes. = My brothers are nearsighted.
• Mis hermanas son miopes. = My sisters are nearsighted.

So:

• singular: miope
• plural: miopes

Because mi is the possessive adjective used before a noun:

• mi hermano = my brother

Mío is a possessive pronoun or stressed possessive form, usually used without the noun or for emphasis:

• Ese hermano es mío. = That brother is mine.
• Un hermano mío = a brother of mine

So in Mi hermano es miope, you need mi, not mío.

Yes, but it is usually unnecessary unless you want emphasis or contrast.

• Mi hermano es miope. = normal, natural
• Él es miope. = He is nearsighted
• Mi hermano, él es miope. = possible, but marked/emphatic

Spanish often leaves out subject pronouns because the verb form already gives enough information.

In Spain, miope is pronounced approximately MYOH-peh.

A rough guide:

• mi = like my
• o = a clear o sound
• pe = peh

The stress falls on the middle syllable:

• mi-O-pe

It matches both; the difference is just regional English vocabulary.

• miope = short-sighted in British English
• miope = nearsighted in American English

So if the meaning has already been shown as either one, that is fine.

Yes, you can, but it means something slightly different in structure.

• Mi hermano es miope. = My brother is nearsighted.
• Mi hermano tiene miopía. = My brother has myopia.

Both are correct. The first is often more everyday and direct in ordinary speech.

Mi hermano es miope is the most neutral and standard word order.

Spanish can sometimes change word order for emphasis or style:

• Es miope mi hermano can be understood, but it sounds more marked or literary, as if emphasizing my brother in contrast with someone else.

For a learner, the normal pattern is:

• subject + ser + adjective
• Mi hermano es miope.

No. That is not correct.

To describe a person with an adjective, you simply use:

• ser + adjective
• Mi hermano es miope.

de is used in other structures, but not here.

Yes. Mi hermano es miope is fully natural and standard in Spain.

In everyday conversation, speakers might also say things like:

• Mi hermano ve mal de lejos. = My brother can’t see well at a distance.
• Mi hermano necesita gafas. = My brother needs glasses.

But Mi hermano es miope is grammatically correct, natural, and standard.