the psychiatric medication you are taking may cause this. it is called extrapyramidal symptoms.
You may require a dose adjustment, please consult your pyschiatrist.
Also the medication may be making you sleepy as well. Are you sleeping well?
This is very important. Take your medication early and sleep early so that you are not drowsy.
How is your vision? Does it just close or there is twitching of the eyelid muscle as well?
Next Steps
If there is twitching the reduce your coffee intake in case you drink coffee, reduce your stress levels and sleep well.
Health Tips
if all this doesnt work you need a neuroophthalmology or neurologist opinion