BACKGROUND: Rigid gas permeable (RGP) contact lenses implanted in the upper eyelid may remain asymptomatic. It is important to evert the upper eyelid even in the absence of definite pain.
METHODS: A 74-year-old woman with a history of rheumatoid arthritis visited a local clinic because of right eye discomfort that had persisted for 5 months. Eversion of the upper eyelid revealed an embedded foreign body, and she was referred to our hospital. A transparent and smooth-surfaced foreign body was found embedded at the center of the upper eyelid conjunctiva. Additionally, fatty tissues were found behind the foreign body. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a foreign body rich in water at the same site. The foreign body was a spherical object with a diameter of 9 mm reaching as deep as the tarsus. On removal, the foreign body was identified as an RGP contact lens. On further questioning, it was discovered that the patient had lost an RGP contact lens 7 years earlier. The symptoms disappeared after removal of the foreign body.
CONCLUSIONS: RGP contact lenses are not detected on MRI scans, but cysts around the lenses are detected, which may result in multiple detections. CT cannot differentiate a foreign body from granulation tissue. The foreign body itself or a reactive granuloma can be seen when the eyelid is everted.
CONCLUSIONS: A contact lens embedded in the eyelid without symptoms is rare but can be detected via a detailed interview, visual examination, and diagnostic imaging.

BACKGROUND: Migration of a rigid gas permeable (RGP) contact lens after trauma is rare, and its clinical characteristics have not been fully discussed.
METHODS: A 36-year-old female showed mild swelling in the right upper eyelid. She lost her RGP contact lens seven months prior to her first visit, from trauma by her child\'s kick to the right eye. At the first examination, we felt a firm lump inferior to the right brow. Eversion of the upper eyelid also revealed a firm subconjunctival mass superior to the upper tarsus. After incising the conjunctiva, the RGP contact lens was found without a fibrous capsule and granulation tissue in the subconjunctival space. Three years after removal of the lens, the patient did not show any complications, including ptosis.
CONCLUSIONS: The RGP contact lens in the present case migrated into the subconjunctival space superior to the upper tarsus without a fibrous capsule and granulation tissue. These findings are similar to those in previously reported traumatic cases but are different from those in some spontaneous migration cases. This difference may be caused by differences in the migration mechanisms.