Ocular prosthetics

F.Ad. Müller Söhne has been involved in the manufacture and fitting of ocular prostheses since 1860. Here we would like to report in more detail about our activities.

Until a few years ago, it was estimated that around one per thousand of the population had a prosthetic eye. This figure is declining as advances in diagnosis and surgical methods are able to save more eyes. The manufacture of ocular prostheses from glass is by no means a new craft. Such an activity was reported in Venice as early as the 16th century.

Material and production

F.Ad. Müller Söhne manufactures ocular prostheses made of glass. The glass we use for the prostheses is inorganic and consists partly of cryolite and partly of crystal glass. These types of glass have proven to be the best in terms of appearance, tolerance and compatibility. They do not contain any substances that are harmful or irritating to the mucous membrane.

The prosthesis lies loosely between the upper and lower eyelid; it is neither operated on nor attached to tissue or muscles. The muscles remaining in the eye socket allow the prosthesis to be moved together with the healthy eye to a certain extent. An ocular prosthesis has the shape of a shell. When customized with the patient, the prosthesis can be single-walled or double-walled. The first type is called a shell prosthesis. The weight of the prosthesis is between 1.3 and 3.5 grams.

The glass material used comes from Thuringia. Glass production has a long tradition in this region. We get the tubes and the basic material for the pupil and iris drawing from there. The basic material for the iris drawing is mixed by the ocularist into color rods that correspond to the iris colors.

Alternatively, ocular prostheses can be made from plastic.

Here you can see a comparison of the two types of prosthesis.

Fabrication and fitting of the prosthesis

Glass ocular prostheses are fitted to the patient during our consultation. Based on the patient’s healthy eye, the ocularist selects an eye color with matching color and iris drawing. There are usually several thousand eye colors available at the treatment location. If necessary, the ocularist checks the old prosthesis and examines the patient’s eye socket to determine the shape and size of the prosthesis. The eye color is then processed with the help of a small burner. First, the ocularist applies a vein meshwork to the prosthesis that matches the patient’s healthy eye. The color and size of the vein mesh can vary.

The vein mesh is then melted into the glass sphere so that the surface is smooth. The eye prosthesis is then shaped to fit the eye socket. To cool down, the eye prosthesis is placed in a steel crucible heated to 500° C so that it can cool down slowly. Once the prosthesis has cooled down, it is tried on by the patient. If corrections are required, these can be made immediately.

As the glass ages and the eye socket can change, we recommend replacing the prosthesis every 1 – 2 years. In certain cases, if the patient has been exposed to heavy environmental soiling, it should be replaced more frequently. The fitting interval for children is shorter due to growth.