Images often carry very private and secret data. Images play an important part in many applications, including remote sensing, healthcare, and defense imaging; as a result, it is important to safeguard such data against misuse and alteration. Encryption is a powerful tool among other forms of data concealment for accomplishing this goal. In this paper, we have done a comprehensive review of image encryption methods based on nature-inspired algorithms. In the present time, nature-inspired (NI) algorithms are used in the encryption process and for key generation purposes in the encryption method. The benefit of NI algorithms is that they enhance the security of the image encryption method by evaluating the security parameters as the objective function. Further, in this paper, we have evaluated several image encryption methods based on various parameters. Next, we have defined the open research challenges in this paper based on the comprehensive review to enhance the image encryption methods.