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.
â¢ People ages 20 to 40 should have an eye exam at least every five years unless there are vision changes, pain, flashes of light, new floaters, injury or tearing. Immediate care is needed to address any of those symptoms.
The College of Optometrists recommends that everyone over the age of 16 should have an eye test every two years, and more frequently if they have an eye problem. Children should have annual tests.