Glass vs. Plastic
The glass eye
- natural inorganic material, cryolite glass (Na6 Al2 F12)
- fire baked surface on front and back side, good wettability with tear film and resistant to liquids
- Colour stable, no fading of the colours
- very light prostheses due to thin walls, an important feature especially with large prostheses due to better wearing comfort (hollow body, not solid)
- the gloss is very close to the natural eye due to the good light reflection
- the preparation takes place in the presence of the patient and, after cooling, the glass eye can be worn immediately (total duration approx. 1-2 hours)
- since only few tools and equipment are necessary, ocularists can be active with their speiialist art in many places, short distances for patients
- fragile when handled carelessly
- can only be corrected or reworked to a limited extent after completion
- repair of damaged glass prostheses is not possible
- at very cold outside temperatures there can, depending on the sensitivity and condition of the orbit, be a cold sensation
- unbreakable (except under extreme loads, as PMMA is made of PolyMethylMethAcrylate)
- no feeling of cold in cold outside temperatures
- can be further altered after production
- wearable for up to 5 years with annual polishing
- less wettability with tear film due to slightly duller surface
- significantly longer production time, (2 days, several visits necessary)
- Reactions with the conjunctiva may occur
- The matte surface has little light reflection even after polishing (mechanically)
- Colour may change over time (fading of the plastic)
- Often heavier than glass prostheses because of thicker or completely solid construction
- A lot of tools and equipment necessary, therefore usually can only be manufactured at a fixed location, often resulting in long distances for patients
- Prostheses made of plastic require an approval procedure with the cost bearers
For how long can the eye prosthesis be worn?
The wear time of the artificial eye depends on various factors, e.g. environmental influence, condition of the socket, strength of secretion, inadequate eyelid closure, etc.. Any eye prosthesis is subject to natural wear and tear due to the effect of the decomposing tear fluid. Thanks to the very resistant material, the wearing time of artificial eyes made of glass is relatively long. It is 1-2 years on average. However, if the prosthesis wearer is exposed to increased environmental pollution, the wearing time can be considerably reduced.
Finally, a few notes
- It is not possible to repair a damaged prosthesis.
- If the artificial eye should break, please keep as many fragments as possible as a template for a new production.
- Optimal fitting of your prosthesis is only possible in person.