If you have ever read the ingredient list on your eye drop bottle, you must have noticed that castor oil is a common ingredient that is found in maximum brands of eye drops. So, what you can do is buy a dropper and use it to suck in pure castor oil and apply 1 or 2 drops each to both your eyes. This has a soothing effect on your eyes and can help to reduce eye irritation. You can repeat this process as many times as you need in a day.