Microglia are the resident macrophages in the central nervous system (CNS), like Kupffer cells in the liver and dust cells in the lung.Cell function is decided by cell properties (like structure determining function) and location.As retina is a part of nervous system, the eyes are an extension of brain.CNS consists of brain, spinal cord and retina.CNS plays a vital role in the body, thus the surrounding microglia based on the ordinary macrophages have many features.Microglia are the sentry of CNS, exerting immune surveillance, immune defense, neuron toxicity, promoting synapse formation and synaptic pruning.Being the most representative immune cells in CNS, microglia become the research focus of nervous system disease pathogenesis.The dual role of microglia in neuron protection and nerve toxicity is due to the different materials synthesized and secreted in response to a series of pathological changes.At present, the study of microglia in nervous system diseases especially retina disease has attracted more and more attention.In this review, the research progress and problems to be solved of microglia in retina disease and nervous system disease involving the retina were described, hoping to provide help in further research on microglia.