The grammar pattern ように見える is used to express that something looks like, appears to be, or seems a certain way based on visual impression or outward appearance. It conveys the speaker's subjective observation about how something or someone appears.
This pattern can follow various forms:
The most common use is to describe how something visually appears to the speaker.
Note: With い-adjectives, you will often see the shorter pattern ~く見える (e.g. わかくみえる若く見える) as well as ~いように見える. Both are natural, but ~く見える is more concise and very common in everyday speech.
ように見える can also express that something seems to be the case based on observation, even if the reality may be different.
You can negate either the preceding clause or 見える itself:
Verb[ない] + ように見える: Appears not to do something
ように見えない: Does not appear to be