What could be causing this sensation?

You're not going to like this:  I had the same sensation - like there was something in my eye - but drops or rinsing did no good . . . . I finally went to my eye doctor.  He gives me the complete exam, then tells me "There's nothing in your eye - your face is just sagging, including your eyelids."  Really.  He said it's normal . . .the only treatment is either cosmetic surgery to tighten everything, or only look up (instead of looking down like holding a book in your lap when reading - hold it up).  Told you that you didn't want to hear this !!!!!!!

Eye mites. Our eyes can't function without tiny little mites keeping the eye clean. Occasionally the little beasts go out of control and since they are creepy crawly critters they give you a creepy crawly feeling.  They go by the name Demodex folliculorum and there's several ways to get rid of them. Several successful home remedies are irritating to the eyes such as rubbing alcohol and tea tree oil. Some home remedies are ineffective such a apple cider vinegar and baby shampoo. Some are untested and unproven such as head and shoulders shampoo to wash eyes.  Predictably effective is medication from the doctor. A visit to a doctor can also tell if it's something else. Of you look up Demodex folliculorum on line you'll find tons only helpful information, things that help, things that don't and other eye problems that also feel like creepy crawly eyelashes. 

That's a sensation you can get as the eyelid swells, even a little bit. That could be the result of a lot of things, like tiredness from too little sleep, eye fatigue in that eye from eye strain (like maybe because of now needing a corrective lens or a stronger prescription), a tendency to rub that eye (often unconsciously) when stressed or tired, dry-eye from excessive screen time (when staring at screens people blink less and over time this can result in dry eye), an infection in the lid (like a sty), and more.

The thing is, since rubbing and pulling increases blood flow, it also increases swelling, so when you have that sensation and then pull at the lashes, you get relief, but what you did will cause more minor swelling, so the relief is temporary and the sensation returns. It's not unlike what happens when you scratch at a swelling caused by a mosquito bite, brief relief only to have the sensation that made you scratch it in the first place return.

I suggest that you go to the drug store and get some anti-inflammatory, lubricating eyedrops, ones specifically for dry-eye. If you can't tell which ones you should get, go up to the pharmacy counter and and ask the pharmacist for help, not any clerk, the pharmacist. That's part of the pharmacist's job. The pharmacist will either tell you what to get or even come out and go with you to the eyedrops to pick out what you need.

Once you've got eyedrops, when you have the sensation, instead of pulling at your eyelashes, put the eyedrops in. Also, adopt a new habit that when you're on your phone or computer, every 10 minutes you spend a full minute looking away from the screen. Thirdly, make sure you're getting enough sleep. Fourthly, if you wear eye makeup, look at what products you're using, specifically if you're using any new ones, using old ones differently, or using any that have gone beyond their expiration date. Fifthly, consider getting your vision tested.

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