Ambio 22: 417-426. soil organic matter and acid soils predominate. case in many of the soils inthe warm-humid tropics. of agricultural and charcoal production. cut and burned to allow planting of crops. cycles before the land has to revert back to fallow. and added to soil.
It's important for adults 40 and older to have eye exams every 2 to 4 years to check for problems. Those who have a history of eye problems or who are at risk for developing them should see an eye doctor every year. This is particularly important if you have risk factors or a family history of eye problems.
After the age of 65 a full eye exam is recommended every year. Julia A. Haller, MD: Small children should be examined every two years, school-age children every year, adults near 40 or over every year - and if you have a family history of an eye disease, get your eyes checked every year regardless of age.