わが目を疑っちゃうなあ。

my; our; one's own

eye; eyeball; eyesight; sight; vision; look; stare; glance; an experience; viewpoint; stitch; texture; weave; ordinal number suffix; somewhat; -ish

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to doubt; to distrust; to be suspicious of; to suspect

hey; say; look; used to get someone's attention or press one's point