I don't get heavy' eyes but I do get sore itchy dry eyes and yes I think it is allergies as mine has been worse this year ..with hot winds and extra hot conditions where I live .I use some eyedrops but they don't help a lot I have had more rashes this year aswell ...
If there is itchiness and watering, the eye symptoms can be due to an allergen. Allergens include pollen, mold, dust and pet dander. But dry eyes can be due to inherent lack of tear secretion and cause pain, light sensitivity, a foreign body sensation and itching. For this the therapy is using artificial tear drops and ointment to lubricate the eyes. But please consult an ophthalmologist for further guidance.
Take Care and Hope this helps!