leaching. Phosphate leached from guano phosphatizes the underlying rocks in some areas, forming apatite where the host rock is limestone and forming aluminum- or aluminum-iron-phosphate minerals where the underlying rock is a silicate. Individual deposits of both igneous apatite and marine phosÂ­
Medicare Part B (Medical Insurance) covers diagnostic hearing and balance exams if your doctor or other health care provider orders these tests to see if you need medical treatment. Medicare doesn't cover routine hearing exams, hearing aids, or exams for fitting hearing aids.
If youâre a Medicare beneficiary hoping to improve your vision with laser eye surgery, Medicare doesnât cover this procedure. Original Medicare, Part A and Part B, doesnât cover routine eye or vision care.Medicare Part A and Part B do cover the costs of certain medical eye conditions if they require hospitalization or emergency care. Original Medicare also covers eye doctor visits and treatments to improve or cure some chronic eye conditions.Two examples are glaucoma and cataracts, but this is not an all-inclusive list, and of course your Medicare-participating doctor must consider the treatment medically necessary.riginal Medicare also covers eye doctor visits and treatments to improve or cure some chronic eye conditions. Two examples are glaucoma and cataracts, but this is not an all-inclusive list, and of course your Medicare-participating doctor must consider the treatment medically necessary.