Decreased blink rate[1] Irritation of the eye surface[1] Alteration in the tear film[1] Visual hallucinations[1] Decreased eye convergence[1] Blepharospasm[1] Abnormalities in ocular pursuit, ocular fixation[28] and saccadic movements[1] Difficulties opening the eyelids[1] This can have particular relevance when driving. People with Parkinson's have been shown to be less accurate in spotting landmarks and roadsigns whilst driving.[29] Limitations in upward gaze[1] Blurred vision[4] Diplopia (double vision), produced by a reduced eye convergence.[27]