Sforno on Leviticus 19:14/ספורנו על ויקרא י״ט:י״ד

1At this point the Torah warns that one must not cause distress to one’s fellow man by undermining his dignity, his self image and the image he enjoys among his peers. Example are: לא תקלל חרש, this is a damage that the deaf person does not even become aware of. Next, the Torah discusses tangible damages, such as

2לפני עור לא תתן מכשול, indirect damages, for who knows if the blind will trip over the obstacle? The one causing even indirect damage is held responsible by the Torah. [this is presumably in the realm of heavenly judgment, seeing that the Talmud feels that people, as opposed to animals, who have eyes in their head, should watch out for obstacles in their path. Ed.]