well, first, you should know that there are many reasons which can cause the dry eye. For example, when you work too hard and have no rest, you may suffer dry eyes. In this situation, you may have both of the eyes become dry eyes. In some cases, your eye will become watery. But on the other hand, if your eyes are infected by some dirty things, it will just irritate one eye, at this moment, you may suffer dry eyes too. on the other hand, the allergies in your eyes can be just caused by allergies, bacteria, some dirty things. And it will make your eyes red , bloodshot.
When your eyes get allergic, your eyes may get the symptoms of swelling eyes, bloodshot or other bad situations. And the allergies of the eyes will not just conclude the symptom of dryness. It will be caused by the wrong eating of spicy food and other things. However, the dryness of the eyes can be caused by the much use of eyes in front of the computers. Whatever the symptom you get, you could treat it carefully.
Of course dryness and allergies are different. The reasons for the two conditions are different. Allergy would be triggered if you get in contact with some subjects that is allergic. It is always associated with other allergic conditions for example, hay fever and dermatitis. If you have eye allergy, your eyes may be burning, itching, watery and swelling. For eye allergies, eye washing is the most common way to flush irritants out. Some over the counter medicine could effectively help relieve the symptoms. As to dryness of eyes, it is the disturbance of tear film. Tear plays very critical role in eyes. It could help wash eyes, kill bacteria and lubricate eyeball. Dryness of eyes is a syndrome which is the disturbance of tear film. With dryness eyes, you might develop redness, grittiness, foreign body sensation and sensitivity to light. Some infections and inflammation might develop dry eyes too. The treatment for dryness is different from that to allergies. Use a humidifier to add moisture in air which could help relieve dryness. Apply hot compress and do some eye massages. The doctor might prescribe some artificial tear and lubricating gel for the patient, which could provide more moisture and lubrication to eyes. Both can be bought over the counter. You can find these differences between the two conditions. Hope this is helpful to you.