Glass or acrylic prosthesis?

F.Ad. Müller Söhne manufactures and customizes glass ocular prostheses. Until 2011, plastic ocular prostheses were also manufactured in our institute. The following is a comparison of the two types of prosthesis.

The glass eye

Advantages

  • natural inorganic material, cryolite glass (Na6 Al2 F12)
  • the surface structure: fire-baked surface on the front and back, good wettability with tear film and resistant to liquids
  • Color stable, no fading of the colors
  • Very light prostheses due to thin walls, an important feature especially for large prostheses, as they are more comfortable to wear (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. After cooling, the glass eye can be worn immediately (total duration approx. 1-2 hours)
  • Since only a few tools and equipment are required, ocularists can work with their craft in many places, short distances for patients

Disadvantages

  • Fragile if handled carelessly
  • can only be corrected or reworked to a limited extent after completion
  • Repair of damaged glass prostheses not possible
  • In very cold outside temperatures, depending on the sensitivity and condition of the eye socket, cold sensations may occur

The plastic eye

Advantages

  • Unbreakable (except under extreme load, as made of PMMA polymethyl methacrylate)
  • No feeling of cold in cold outside temperatures
  • Can be further modulated after production
  • Wearable for up to 5 years through annual polishing

Disadvantages

  • Poorer 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 matt surface has little light reflection even after polishing (mechanically)
  • The color may change over time (fading of the plastic)
  • Often heavier than glass dentures, as they are thicker or completely solid
  • No preparation of a bulbar scleral shell possible to cover an eye that should not or cannot be removed by enucleation
  • A lot of tools and equipment required, therefore usually only producible at a fixed location, resulting in long distances for patients
  • Prostheses made of plastic require an approval procedure with the cost bearers