Retinal degeneration is a leading cause of blindness. With recent developments in 3d-printing technology it is possible to actually print eye cells. The added precision with a 3d-printer can arrange the cells in the complex arrangements necessary to function. Retinal damage is a three dimensional problem requiring layers of cells intricately placed. Researchers at Cambridge hope to use this technology to grow and print eye cell cultures outside of the body then surgically implant them to the damaged tissue. These researchers have succeeded in making printable suspensions of two different cells, retinal ganglion and mature neurons, essential in the function of the eye. Mature neurons have not been successfully printed until now due to the frailness of the cells.

It has been mentioned before why 3d printing organs is so difficult. Organs more often than not have more than one type of cell. These different cells interact with various types of tissue. Flat structures like skin are generally one type of cell and thus easier to print. Successful implementation and arrangement of all the types of cells is what is currently hindering bio-printing. With more than one type of eye cell printed in solution, it is clear that the precision and abilities of 3d-printing are improving.