Posts Tagged ‘myths’

Myth #4: Artificial Eyes are Made of Glass

Monday, January 4th, 2010

Okay, so this one’s actually true. Artificial eyes have been and do continue to be made of glass in some parts of the world. In United States, blown glass has not been used to make artificial eyes in over 65 years. Please see our history section for more explanation of this. The current material for making artificial eyes is acrylic. Poly-methylmethacrylate or PMMA for short. Acrylic is an excellent material due to its very low reactivity with human tissue. The acrylic is also a very smooth material that is very strong. Acrylic is actually more transparent than glass, hence it’s widespread use in aquarium enclosures, rather than glass.

For our benefits, acrylic is a very good material to work with. It can be added to and subtracted from relatively easily and is very durable. Most ocular prosthetics last 5 years, but not because of the material. Usually the fit of the prosthesis has changed due to the constant changing of one’s own ocular tissue. The acrylic will usually do quite well in the socket until about 10 years when the pores will begin harboring bacteria.

Acrylic eyes do require maintenance to keep the surface smooth and free of bacteria. A professional polish every six months is recommended for most patients. This allows the ocularist an opportunity to inspect the fit, health of the socket and also remove protein and bacteria that form in the pores of the acrylic. If it has been more than a year since your last polish, please contact your ocularist.

Myth #3: Artificial Eyes and Scleral Shells Are Cosmetic

Saturday, December 19th, 2009

It is very rare that we come upon an insurance company these days who believes that artificial eyes or scleral shells are cosmetic. The medical necessity for wearing an artificial eye or a scleral shell is to bring about the natural functions of the eye socket. These include proper drainage of tears, creation of tears, protection of the mucosal tissue from drying out and contracting, protection from infection and bringing the phthsical globe or anophthalmic socket back to full size. These reasons alone are enough to provide medical necessity, yet there are of course other benefits to wearing an artificial eye or scleral shell. If you have difficulty with your insurance company considering this a cosmetic procedure, please contact your ocularist for assistance.

Myth #2: Artificial Eyes Do Not Move

Tuesday, December 15th, 2009

It seems that most everybody has a great uncle twice removed who had an “glass eye” that did not move. Contrary to popular belief, most modern artificial eyes and scleral shells move quite well. Movement of the artificial eye is dependent on the movement of the tissue behind the prosthesis and the fit of the prosthesis to this tissue.

Movement could be broken into a couple different categories:

  • Conversational Motility
  • Moderate Motility
  • Extreme Motility
  • Blinking

Motility is the movement of the eye, it includes conversational movement and the movement of the eye all the way to the extremities. Most patients we see experience very good conversational motility. We consider conversational motility to be the horizontal and vertical movement of the prosthesis in the first 10 degrees in each direction. This is the most common movement of the eye, the quick darting movements we all make during interactions with others.

Moderate motility is movement past the 10 degrees of conversational motility, but movement that falls short of the extremities. The degree of motility of an ocular prosthesis is most dependent on the movement of the ocular tissue or ocular implant placed by the surgeon. A nicely placed orbital implant that is central in the orbital cavity and appropriately attached to the major ocular muscles, will be well positioned to provide very good motility. A second factor in motility is the fit of the prosthesis to the orbital implant. Erickson Labs Northwest utilizes the modified impression technique that provides the best possible junction between the front of the orbital tissue and the posterior of the prosthesis, allowing the best possible movement.

Extreme motility is the movement of the eye all the way to the extremities. Extreme motility is more rare due to the anatomical design of the eye socket and the necessary shape of the artificial eye. Extreme motility is often seen in patients wearing a scleral shell over a nice full sized or phthsical globe. Extreme motility can also be seen in patients fitted with a motility implant and integration system such as a titanium peg.

Blinking is the vertical movement of the eyelids, mostly the superior lid, to close and open again. While blinking is not motility, it is very important to the realism of an artificial eye. Blinking functions to wet the ocular surface creating a tear film, promote creation of tears from the eyelid glands, pumping excess tears to the tear ducts, and clearing the ocular surface of debris. Proper blinking is very important to the health of the anophthalmic socket and the normal appearance of an artificial eye.

Myth #1: Artificial Eyes Are Round Spheres

Tuesday, December 1st, 2009

Pirates of the Carribbean Wooden EyeThis is perhaps one of the most common misperceptions new patients have about artificial eyes. I think Hollywood has done an excellent job perpetuating this myth! Imagine the round wooden eye rolling down the deck of the pirate ship in Pirates of the Carribbean. While it is possible that an artificial eye could be made in this shape, it would be VERY rare. Most artificial eyes are shaped in what we call the reform shape, where the front is curved similar to a natural eye and the back is impression molded to the existing tissue. The existing tissue owes its shape to the orbital implant – which most often is a sphere. The resulting shape of the artificial eye is like a large contact. The thickness is determined by the space between where the orbital tissue is and where the front of the cornea should be on a natural eye. Our regards to Captain Jack Sparrow and his crew, but this one is a myth!