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Paper text:
an 83-year - old female with a left upper lid swelling was referred by her physician .
she reported having this gradually enlarging , painless swelling for the last 23 years , which was now causing her eyelid to droop .
there was no history of any ocular trauma or lid surgery . on examination , a freely mobile 2 cm  3 cm
cystic swelling was noted in the left upper lid , which was causing an upper lid ptosis of 1 mm [ fig .
a presumptive diagnosis of chalazion was made and an incision and curettage was performed . during the procedure ,
a soft silicone hydrogel contact lens with granulation tissue was noted at the base of the cystic lesion and removed [ fig .
, it transpired that 13 years previously she had lost a soft contact lens from her left eye .
she assumed that it has spontaneously fallen out and she never went to see an optician or an ophthalmologist . following this incident
( a ) small left upper lid swelling suggesting chalazion ( b ) soft hydrogel contact lens after surgical exploration
contact lens wearers very commonly lose a lens . on occasion , it may be assumed that it has fallen out spontaneously when in fact the whole lens or a torn fragment has been retained .
usually , these follow symptoms of irritation resulting in the lens being recovered , but occasionally it can be retained for many years without any symptoms as has been reported previously with hard contact lenses .
perhaps , a soft contact lens has more chance of remaining in the fornices without any symptom due to the nature of the material .
this case highlights how a retained conjunctival foreign body , such as a soft contact lens , can migrate through the palpebral conjunctiva and levator aponeurosis to a new location just anterior to the tarsal plate .
2 ] the pathway followed by migrated contact lens the chronic trauma and irritation caused by the misplaced lens may be asymptomatic from the patient 's perspective ; this is probably due to the soft and hydrophilic nature of the contact lens material .
postulated that the sequestered nature of conjunctival epithelium may be responsible for minimal tissue reaction to soft contact lenses .
as suggested by freidberg et al , a retained hard contact lens presenting as lid swelling is not uncommon , but to our knowledge , migration of a soft contact lens in this way has not been reported previously .
this case highlights the importance of a thorough ocular examination including double eversion of the upper lid and sweeping of the fornices with cotton bud in a patient with lost or mislocated contact lenses , and is possibly more important in soft than hard contact lenses .
a misplaced contact lens is a common ocular emergency presenting to the eye casualty . 
 we report a case of lost soft contact lens which migrated in the lid and presented 13 years later with symptomatic eye lid swelling . 
 authors in the past have reported migration and subsequent retention of lost hard lenses in locations such as the superior fornix and eyelid . to the best of our knowledge , misplaced soft contact lens masquerading as a chalazion has not been reported in the literature . 
 consideration should be given to the possibility of a retained contact lens in a patient with a history of a lost or misplaced lens , and examination of the ocular surface with double eversion of the upper lid should be performed .