Yes, MoodWhiplash is pretty correct.
miru 見る
mieru 見える
miteru/miteiru 見てる/見ている
These three forms show the difference of tense. And additional status of sense modes.
ジェインは、花を見る Jein wa hana wo miru :: Jane looks at a flower. Jane sees a flower (flowers).
Basically "present", and sometimes "future". e.g. ジェインは、明日、花を見る :: Jane will see the flower tomorrow.
(ジェインには)、花が見える (Jein ni wa) Hana ga mieru :: (For Jane), Flower is there (in the vision, in the scope of sight).
"Present". And this is not "active", nor "passive". But "Neutral mode".
Not the structure of "Subject V Object". No subject.
Also, "mieru" shows possibility.
Nani ga miemasuka? - Hana ga mieru. ( What can you see? - I can see a flower.)
ジェインは、花を見てる Jein wa hana wo miteru :: Jane is watching a flower. Jane is seeing a flower. etc. [progressive]
And in addition. :: Jane has been watching a flower. [present perfect, progressive]
(Why "present perfect, progressive"? There is this kind of expression:
ジェインは、五時間前から、花を見てる Jein wa go-jikan mae kara, hana wo miteru :: Jane has been watching a flower for 5 hours (since 5 hours ago).
神は、ジェインが子供の頃から、十年間、彼女を見てる :: The god has been watching Jane for ten years since she was a child.
In this case, "The god is watching Jane for 10 years since she was a child" is strange.
(Well. Do not say, for god, there is no time. god is in present. god is in the Aeon. In all the time.)
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thus:
Miru :: [present] and [future] tense
Mieru :: /Neutral mode/ or /possibility/
Miteru :: [present progressive] and [present perfect, progressive] tense and mode
_ mrd