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.
Children should have an eye exam every two years or more often if there is an eye or vision problem or a family history of eye disease. School children use their eyes more often than adults to read and perform other activities, so it's critical for them to have regular eye exams.