I know the first one:
The person might have trouble seeing shades of red, blue, and/or green. Color-sensitive pigments in the cones of the eye are absent. These inabilities to see certain colors ends up leading to the person seeing the colors in question as a mixture of the same shade.
Human activities that contribute to desertification include the expansion and intensive use of agricultural lands, poor irrigation practices, deforestation, and overgrazing.
Answer:
Russian revolutionary, politician and political theorist
