I have newly been diagnosed with dry eyes and I am worried. What might be the cause of it? Is this conditionserious?

Not uncommon. Dry eyes are a common development with age. Certain medicines, contact lens use, smoking, sun and wind exposure, and lasik may make them worse. If they are not associated with any more serious systemic diseases, then they are not too worrisome, just another "benefit" of advancing age.
Dry eye. Dry eye is common and can be easily treated in the vast majority of patients. See your eye doctor for a complete evaluation and treatment.
Get more info. Dry eye syndrome (or dysfunctional tear syndrome) can have different levels of severity from only symptoms to significant damage to the ocular surface and vision loss. Causes can also vary from normal aging changes to associated systemic disease to ocular surface damage. Ask your doctor for more information about your condition and/or seek a dry eye specialist.
Treatment helps. There are many treatments available for dry eyes. Increasing the mositure in the environment with a humidifier, dietary changes like increasing fish oils and omega three fatty acid intake, over the counter artificial tears, prescription drops (restasis), and plugs in the tear drainage ducts are all successful in some patients. The symptoms of most patients can be reduced.