Here is a list of eye sizes provided by various doll manufacturers, which I recently organized. Everyone is welcome to add or refine this information:
WM TPE: 32mm
Angel Kiss: 30mm
Irontech TPE: 32mm
Irontech Silicone: 26mm
6YE TPE: 30mm
Zelex: Varies for different dolls
Jiusheng: 27mm
MLW: 27mm
SM Silicone: 26mm
CST: 35mm
Elsababe: 26mm
Feel free to contribute any additional information or corrections to this list.
Additionally, if anyone is interested in replacing their doll's eyes with various styles, feel free to visit:
https://www.coeros.com/collections/sex-doll-eyes/