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After going through the details , absence of pain in the left eye helps to know that there is no corneal inflammation( keratitis
- an important cause of redness of the eye especially in those who wear contact lenses
). That does leave us with the probablity of dry eyes
and giant papillary conjunctivitis( allergic condition seen with chronic use of contact lenses
though less in daily or monthly disposable types). As you have also got known allergies to dust , it all the more suggests the symptoms to be due to allergy. You have started with lubricating eye drops and allergy eye drops which is good enough in mild cases. If symptoms have persisted inspite of that then it would be better to try preservative free Refresh tears eye drops for lubrication ( continue your drops if the same), Olopatadine eye drops ( prescription eye medicine) helps to treat eye allergy. For the lid swelling ( most probably the cause for lid droop also), you can tab.cetrizine 10 mg once at bedtime for 2 weeks ( oral anti-histaminic).
Since your present medicines have not given you the desired relief, I suggest that you get your eyes examined by an ophthalmologist
( a slit lamp examination will help to know the status of the cornea and to detect the cause for the photosensitivity). Also the above mentioned prescription medicines can be started.
Thank you and best wishes
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A bonus and positive feedback are welcome.Views expressed are for information purpose only and cannot substitute a visit to an ophthalmologist