After long hours of studying as a graduate student, Saad Bhamla's eyes hurt. Contacts and intense visual focus just didn't go together.
He resolved to make contacts more comfortable and now, as a postdoctoral scholar in bioengineering with a PhD in chemical engineering, he's taken a step to do just that. As reported in a Stanford News release:
Bhamla and [chemical engineer Gerald Fuller, PhD,] suspected that most of the discomfort arises from the break up of the tear film, a wet coating on the surface of the eye, during a process called dewetting. [In a study,] they found that the lipid layer, an oily coating on the surface of the tear film, protects the eye's surface in two important ways – through strength and liquid retention. By mimicking the lipid layer in contact construction, millions of people could avoid ocular discomfort.
The engineers and their team then designed a device that mimics the surface of the eye, which they can use to test contact lenses:
The machine, called the Interfacial Dewetting and Drainage Optical Platform, or i-DDrOP, reproduces a tear film on the surface of a contact lens. It allows both scientists and manufacturers to systematically handle the unique array of variables that affect the tear film, including temperature, a variety of substances, humidity and the way gravity acts along a curved surface.
With the ability to accurately recreate a tear film on the contact lens surface and test how quickly it breaks up, manufacturers are now armed with the tools to make a more comfortable lens that protects users from the painful side effects of wearing contacts. Even Bhamla may trade in his glasses for a new pair of lipid-protected eyewear.
Their study appears in the journal Investigative Ophthalmology & Visual Science.