"视力很差"用英语可以说成"have poor vision"。
"vision"是英语中眼睛的意思，"poor"是差的意思。结合在一起就是"视力很差"。
例句1: "I have poor vision and need to wear glasses." (我的视力很差，需要戴眼镜。)
例句2: "I have poor vision in my left eye." (我左眼视力很差。)
例句3: "Due to poor vision, he can't drive at night."(因为视力差, 他不能在晚上开车。)