Based on our data the membrane potential of RGCs, and therefore levels of excitability, are likely sensitive to a wide range of physiological and pharmacological factors to which K2P channels show sensitivities. For example TASK-1 channels are characteristically sensitive to changes in extracellular pH and hypoxia686970, whereas TREK-1 channels (and TREK-2 and TRAAK) are mechanosensitive, temperature sensitive, and are directly modulated by lysophospholipids and polyunsaturated fatty acids (PUFAs)27467172. By contrast TWIK channels typically show lower levels of modulation compared to other K2P channels and can be considered as more typical K+ leak channels16. It would therefore seem that K2P channels are well placed to act as central regulators of RGC excitability (and therefore photosensitivity) under a wide range of conditions. We propose that the differential profile of K2P channel expression likely contributes to the functional diversity of RGC subtypes7, and offers a potential mechanism to fine tune the functional properties of individual RGCs under specific physiological conditions. Further work will be required to determine if the differential expression of K2P channels contribute to the different levels of sustained and transient activity observed from distinct subtypes of RGCs9.