**7. Conclusion**

Optogenetic retinal prostheses fundamentally has the potential to restore quality vision in the human retina. Although there are certain limitations and challenges associated with opsin characteristics and delivery methods, in the coming years, repetitive clinical trials with new opsins and safe delivery methods would allow the efficient design of optogenetic retinal prosthetic devices and circuits. Theoretical studies in optogenetics have the potential to guide future experiments with reduced irradiance and enhanced visual contrast. Future experiments by co-expressing excitatory and inhibitory or spectrally orthogonal opsins into different retinal neurons *e. g.,* ON and OFF type of RGNs, would significantly improve the quality of restored vision.
