Ocular dysmetria is a form of dysmetria which involves the constant under- or over-shooting of the eyes when attempting to fix your gaze on something. It is a rather upsetting sick-making condition that makes you want to close your eyes to avoid it.
Ocular dysmetria indicates lesions in the cerebellum which is the brain region responsible for coordinating movement. It is a symptom of several neurological conditions including multiple sclerosis.
HyperBrain glossary - Ocular Dysmetria
Saccadic downpulsion and cerebellar disease