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.

Many causes but you can try Pataday eye drops twice & genteal eye drops 4-5 times for a week & if you don't get relief consult ophthmologist, with regards

There can be multiple cause. If no discharge then simply put lubricating eye drops.