ansehen
to look at
To direct one's gaze at someone or something; to look at.
Sieh mich bitte an, wenn ich mit dir rede.
Please look at me when I'm talking to you.

to look at / to watch
Loading your saved state.
to look at
To direct one's gaze at someone or something; to look at.
Sieh mich bitte an, wenn ich mit dir rede.
Please look at me when I'm talking to you.

'Ansehen' (to look at / to watch) is a separable verb with the prefix 'an-'. In main clauses, 'an' goes at the end, while in subordinate clauses it remains attached to the verb. In the infinitive with 'zu', 'zu' comes in the middle.
Sieh dir dieses Bild an!
Look at this picture!
The non-reflexive form 'jemanden ansehen' (to look at someone) means to direct one's gaze at someone. The reflexive form 'sich etwas ansehen' (to look at/watch something) means to look at something more closely, inspect it, or consume it as a spectator.
Der Arzt sah den Patienten besorgt an.
The doctor looked at the patient with concern.
The construction 'jemanden/etwas als ... ansehen' (to regard someone/something as ...) is used to express an opinion or judgment. What someone is considered to be is also in the accusative after 'als'.
Viele sehen diese Entscheidung als einen großen Fehler an.
Many regard this decision as a big mistake.
The idiom 'man sieht es jemandem an' (you can tell from looking at someone) means that a person's appearance reveals their feelings or state. The person in question is in the dative.
Man sah ihm die Erleichterung deutlich an.
You could clearly see his relief.
In the reflexive form 'sich etwas ansehen' (to look at/watch something), the person looking at something appears as a reflexive pronoun in the dative ('sich'), and the thing being looked at is in the accusative. This applies both to watching films and to viewing places.
Ich sehe mir heute Abend einen Krimi an.
I'm watching a crime thriller this evening.
Careful: 'das Ansehen' (reputation/prestige) is a noun and means 'reputation' or 'prestige'. It is always capitalized and has a completely different meaning from the verb 'ansehen' (to look at / to watch).
Der Professor genießt weltweit hohes Ansehen.
The professor enjoys a high reputation worldwide.
to see
'sehen' and 'ansehen' overlap when it comes to perceiving with the eyes. 'sehen' is more general: you perceive something or, for example, watch a film. 'ansehen' more strongly emphasizes that you deliberately direct your gaze at someone or something. For films, theater, or sports, people often say 'sich etwas ansehen' when they are spectators. In addition, both can express an opinion or judgment in phrases like 'als etwas sehen' and 'als etwas ansehen' (to see/regard as something). Learners confuse them because both can fit in similar sentences. 'sehen' is more neutral and broader; 'ansehen' sounds more deliberate.

Fiona sieht sich morgen die neue Wohnung an, bevor sie den Vertrag unterschreibt.
Fiona is looking at the new apartment tomorrow before she signs the contract.
Die Gruppe sieht das Spiel zu Hause, weil das Stadion zu weit weg ist.
The group is watching the game at home because the stadium is too far away.