If a girl gets sperm in her eyes, will she get lazy eyes?

No. But it could cause conjunctivitis. That's all I have to say on this one.
No. Amblyopia is generally caused by misfocus, misalignment or blocked vision and usually occurs in children less than 7-8 years of age. Semen may transmit a std but will not cause amblyopia. There are serious social considerations if a child gets semen in her eyes in the amblyopia age range!