Every artificial eye is an individual custom-made product that in its colour, shape and size is optimally made to suit the needs of every patient. Hereafter you will know exactly the materials of which the artificial eye is made and the technics.
But also some synthetic materials are employed.
The artificial made of glass
In Germany and other European countries, glass eyes have been made for many years and are usually manufactured from a special form of glass (cryolite glass) that is highly biocompatible and which does not include any chemical additives.
Manufacturing of prosthesis made by glass
The extremely smooth surface of the glass means that a permeable tear film can form on the eye. In this way, the glass eye may be worn comfortably and without it feeling dry. Glass is also ideally suited to the manufacture of prosthetic eyes because of its high resistance to the harmful effect of the lacrimal fluid. There have been no allergic reactions to glass reported.
The principal material of our artificial eyes is the cryolite glass. This is a white special glass which becomes translucent at high temperatures and can so optimally handled. It has been specially developed for artificial eyes and is produced by specialised glassworks.
The coloured parts of the eye prosthesis are also made of glass, no chemical additives are used. Iris markings, pupil, veins etc. are melted onto the cryolite glass with the aid of special coloured glass.
Glass artificial eyes have a long tradition in Germany and are the normal standard for ocular prostheses. The costs are covered by the health insurance provider.
Prosthesis made of synthetic material
In some cases, it may be sensible to opt for a prosthetic eye made of synthetic material rather than glass. This is especially advisable if there would otherwise be the danger of a glass eye frequently breaking, e.g. with people who are unable to grasp objects, patients with Parkinson ’s disease, etc.
Eyes made of synthetic material are subject to a significantly quicker deterioration than glass prosthetics as the synthetic material has a demonstrably softer surface that is easier to damage. However, unlike glass, these prosthetic eyes can be repolished, which, in most cases leads to a longer life.
As synthetics are water resistant, there is no complete, natural tear film on prosthetic eyes made of synthetic material. This can lead to lid and conjunctival irritation and create the feeling of dryness. Furthermore, allergic reactions to artificial eyes made of synthetic material are also possible. Last but not least, every prosthetic eye made of synthetic material is subject to separate approval by the health insurance scheme.
Our institute specialises in the manufacture of glass eyes. However, we can also make artificial eyes made of synthetic material for you. So please speak to us if you think that wearing a prosthetic eye made of synthetic material is sensible for you. We’ll gladly give you advice.
Manufacture of glass eyes
A glass eye is produced in three stages that build upon each other:
1) The blank with the sketch of the iris
The base material for the manufacture of our artificial eyes is a tube of white cryolite glass, from which a sphere is blown. So as to copy the individual colouring and structure of the iris, in the next stage, coloured glass is put onto the white sphere with diverse, specifically made colouring rods, in parts, layer upon layer. After adding the pupil with black glass, the anterior chamber of the eye, the cornea is reproduced. Through this, the design of the iris gets its own spatial depth.
The sphere with the complete design of the iris forms the basis for the individual production of the prosthesis. For this purpose, we always provide about 3,000 blanks. And if we do not happen to have a specific eye colour in stock, it is manufactured on-site for the patient.
2) The custom requirement of the eye colour
The customized iris colour is selected and adapted further together with the patient. For this purpose, the size requirement of the iris must match that of the remaining eye as must the correct copy of the veins and the cloudiness of the white part of the eyeball, the sclera. Age-related eye changes, as for instance arcus senilis or increased visible veins are also individually incorporated by our ocularists into the prosthesis.
The pupil of a healthy eye constantly adapts to the prevailing light conditions. A glass eye can’t behave in the same way. So we select an “average size” for the pupil which matches the mean normal condition of the patient’s pupil diameter.
3) The custom requirement of the shape
Now the prosthetic eye gets its shape that is unique to every patient. Here, there are two variants: the double-walled reformation eyes and the obviously thinner shell eyes. Double-walled prosthetic eyes constitute the common treatment for empty eye sockets. On the other hand, single-walled shells are used in the case of very narrow spaces within the eye socket and to cover an eye that has lost its sight (in this case called the bulb scleral shell).In both cases, the original sphere gets the necessary individual shape by melting away the superfluous glass material, a millimetre at a time. Finally, at the end of this stage, the completed, semicircular prosthetic eye is ready.