Hi Fudgeley dogs can develop an allergic reaction to many substances including various pollens so I suppose you could say they can have a type of hayfeaver.

There are various canine antihistamines available from the vet if a reaction is severe , Atarax is one.

Another treatment for pollen related allergy is if you have a local beekeeper to give your dog honey made within five miles of where you live (that is the distance bees are thought to gather pollen) this will help to desensitise your dog to the local pollen .

Have you changed any cleaning products recently or added scented room fresheners, these can cause a reaction in some dogs.
The red eyes could also be conjunctivitis caused by a mild infection. I would bath them in a mild saline solution made from a pint of boiled water a teaspoon of salt taking care to use a clean piece of cotton wool each time you put it in the liquid and for each eye to prevent cross infection. As you are going to the vet anyway he may be able to diagnose any problem .