(verb) to have night blindness; (slang) to describe someone who has failed to see or notice something, often used as a way of scolding others with a similar meaning to "are you blind or something?" / "look where you are going!"
Definitions (粵典–words.hk)
動詞
鬧人睇唔到啲好明顯嘅嘢 to fail to notice or to find something which is obvious; to not see something; to be blind to something
咁大個電話喺枱面你都見唔到，你發雞盲呀。
咁大个电话喺台面你都见唔到，你发鸡盲呀。
gam3 daai6 go3 din6 waa2 hai2 toi2 min2 nei5 dou1 gin3 ng4 dou2, nei5 faat3 gai1 maang4 aa4 So big is the telephone on the table and you can't see it. You are blind?
撞乜嘢呀撞，發雞盲架你？
撞乜嘢呀撞，发鸡盲架你？
zong6 mat1 je5 aa3 zong6, faat3 gai1 maang4 gaa4 nei5 You must be blind to bump into me.
Definitions (Wiktionary)
verb, Cantonese, derogatory, verb-object
to not see something clearly noticeable
verb, Cantonese, verb-object
to have night blindness