Direct or indirect are no categories for objects in German grammar. German categories for Objects are: Dativobjekte (objects in dative case), Akkusativobjekte (objects in accusative case), Genitivobjekte and others (Nominativobjekte, Präpositionalobjekt, ...).
The verb in the sentences predicate dictates in which case its object(s) have to be. You have to learn for each verb with which types of objects it can be combined, but this is not so hard like learning the articles of nouns, since it is more systematic. Verbs with similar meanings normally come along with the same types of objects.
The verb »helfen« (to help) has this possible objects:
- Who is receiving help? - Dativ
Karl hilft dir. - Karl helps you.
- (rare) Who is helping? (can only be used if this information is not given in the subject, where it normally is) - Akkusativ
Lass mich helfen! - Let me help!
You can combine both:
Geht zur Seite! Lasst den Arzt(Akk.) der Frau(Dat.) helfen! - Step aside! Let the doctor help the lady!
But you can use the verb also without any object:
Wir helfen gerne. - We're glad to help.
(Note, that in the last example the predicate of the German sentence is »helfen« while in the English sentence it is »to be glad«. So it is not a 1:1-translation. A translation that keeps the German grammar would be »We help gladly«, but I guess it is not the best English translation)
First of all: You obviousely have a wrong translation in mind. The sentence »Kannst du mich sehen?« is not »
Are you looking at me?«. It is »Can you see me?« So you don't ask for the object with » for/to whom« but with »who«. But anyway: English questions don't always give the correct hint for German grammar.
This is the possible object for sehen:
And also sehen can be used without Object:
Ich habe eine neue Brille. Ich sehe jetzt besser. - I've got new glasses. I see better now.