Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. A major risk factor is increased pressure in the eye. The disorders can be roughly divided into two main categories:  open-angle  and  closed-angle  (or  angle closure ) glaucoma.laucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. A major risk factor is increased pressure in the eye. The disorders can be roughly divided into two main categories:  open-angle  and  closed-angle  (or  angle closure ) glaucoma.
Q: A geochemical cycle that cycles material by mantle convection, subduction, and seafloor spreading is A: A geochemical cycle that cycles material by mantle convection, subduction, and seafloor spreading is TECTONIC. Weegy: erosion. The rock cycle includes the formation, breakdown, and reformation of a rock as a result of sedimentary, igneous, and metamorphic processes.
Whole-mantle convection describes a long, long recycling process involving the upper mantle, transition zone, lower mantle, and even Dââ. In this model, the mantle convects in a single process. A subducted slab of lithosphere may slowly slip into the upper mantle and fall to the transition zone due to its relative density and coolness.