Orbital metastasis of lung cancer is rare. It often causes visual disorder. To 
date, there are only a few case reports. Crizotinib is an anaplastic lymphoma 
kinase (ALK) tyrosine kinase inhibitor that leads to responses in most patients 
with ALK-positive non-small-cell lung cancer. Visual disorder is one of the 
popular adverse events of crizotinib, but the symptom almost decreases over 
time. We report a case of orbital metastasis as the disease progression of 
ALK-positive lung cancer treated with crizotinib. It should be kept in mind that 
orbital metastasis can be the disease progression of lung adenocarcinoma with 
ALK translocation treated with crizotinib. When physicians encounter a patient 
receiving crizotinib with visual disorder, we must distinguish between adverse 
events and orbital metastasis.