Hello there are many causes for redness of eyes mainly allergy, infection, inflammation and dry eyes etc. 1. Redness + itching: allergy 2. Redness + pain + watering + decreased vision: infection 3. Redness + pain: inflammation 4. Redness foreign body sensation: dryness if there is only redness then it is normal as slight exposure to dust, temperature or air or eyes may be red in morning. Stress may also cause redness. I usually do not treat when there is only redness, you can 1. Blink a lot 2. Wash eyes with fresh water 3. Cold compresses 4. Use lubricating eye drop like flogel these measures will help to keep your eyes healthy but it will not have any effect on redness (treating general redness alone is not necessary also) having said that you should consult local ophthalmologist for proper examination and treatment.

Your description points towards ocular allergy,it will disappear with anti allergy eye drops but it will appear  when you stop putting eye drops so needs no medication. Sometimes with change of place it disappear.

Symptoms you have described points towards  ocular Allergy and associated dryness.. Consult a Ophthalmologist,who will put you on maintenance medications as simple as once a day on a long term. These are very safe even on long term.