Jason was born crossed-eyed and did not have the problem surgically corrected until he was 7 years old. Now, Jason has severely impaired depth perception. This impairment developed because Jason missed for developing depth perception.

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.