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Juliana Haddad ’23

2021 SOAR Profile

Characteristics of Photochromic Lenses

Major and Minor: Biochemistry with a Business Management minor
Hometown: Bethlehem, PA
Project Advisor(s): Dr. Kelly Krieble

Briefly describe your project.

This project aimed to investigate the characteristics of photochromic lenses and compare similar lenses across a variety of brands. This project also aimed to research any external factors that affect the function of the photochromic lenses such as light source, temperature, intensity, and many more.


Juliana Haddad ’23

Describe the origin of your project. (E.g., did you pitch the idea and choose a faculty member, or did they come to you with an idea?)

I have always had a passion for optics. In the spring semester before the summer of this project, I sent an email to Dr. Krieble asking if he would be interested in supervising a research project in the summer. He said yes and proposed this idea and it was pretty interesting to me.

What’s the best part about working with your faculty mentor? What valuable insights have they brought to your project?

The best part for me was analyzing the results with Dr. Krieble. After collecting the data for each experiment, I would ask Dr. Krieble to take a look and evaluate the results I got. This was the best part because it taught me to think critically, always ask more questions and not settle for “good enough” results.

Additional insights I have learned from Dr. Krieble is there is always a way to solve something and one should not give up in the face of difficulties. We are in control of the setup and not the other way around. His dedication to the project and enthusiasm about research brought joy to my project and I aim to develop a passionate personality like his one day.

What has been your biggest obstacle so far?

The biggest obstacle was to develop an apparatus that changes the temperature of the lenses in both direction (ie. heating up and cooling down). We have tried using a blow dryer to heat the lens, it gave good results but it was a one way change only, we could not cool the lens with it and it was very loud as well. On the other hand, we have also tried using liquid nitrogen to cool the lens down but it was around a two-hour wait to see a slight change in the temperature. Changing back and forth between these two setups cost us a lot of time, and a lot of variation in the data as well.

Another big obstacle was trying to figure out the molecular formula of the dyes used in the lenses. The brands kept this information confidential and did not share them on their website, manuals, or any other resource. Because of this, we could not figure out the biochemistry aspect of photochromism completely, and we had to make a few educated guesses.

What has been your biggest takeaway from this experience?

My biggest takeaway is that research is a continuous project; you need to be able to ask questions, work your way around things, and be as patient as possible. I also learned the importance of relying on yourself and trying to find solutions to minor problems on your own. Even though I have asked Dr. Krieble’s advice on so many minor issues, I also tried to solve some problems to save him some time and also for me to learn to depend on myself.

What was the result of your project?

During the project we have reached some conclusions about photochromic lenses and photochromism in general, they are summarized in the following points:

  • The darkening and fading processes of the photochromic lenses follow the double exponential model.
  • Darkening: Absorbance=A(1-exp(-x*ln(2)/C)+1-exp(-x*ln(2)/D))+E
  • Fading : Absorbance=A(exp(-x*ln(2)/C)+exp(-x*ln(2)/D))+E

An increase in the temperature of the lens leads the half lives of the darkening and fading processes to go down where a decrease in temperature leads the half lives to go up which explains why your transition lenses would darken more in the winter than in the summer as it would be fading slower in the winter. Also, an increase in the intensity of UV light source is negatively correlated with the time it takes for the lens to darken and vice versa.

A clear comparison between the brands (Shore) and (Transitions) is not complete yet; however we can conclude that the observed photochromism effect in both brand lenses is a result of an organic reaction that involves dyes of unknown structures reacting in a double exponential equilibrium model. The dyes are believed to be T-type.

In your own words, how do you feel about being awarded this opportunity? Why should other students take advantage of the SOAR program at Moravian University?

When my application to the SOAR project was accepted, I felt excited and grateful as this is an opportunity for me to gain more knowledge in the optics field, and also to develop additional experience in terms of collecting, analyzing, and presenting data. The summer semester is a great time to start a research project because you can dedicate more time to the project and still have free time outside of school. This would not be the case during the fall or the spring semester because the student has to work out their time between classes and research. Another reason to consider SOAR is to develop your character. Coming to campus on summer break can be hard at first, but it teaches you dedication and helps you build your character outside of school.

Now that SOAR is over, do you plan to expand upon your research? If so, how?

I would definitely consider expanding my research in this field. Further research may focus on observing the temperature role in the darkening and fading processes of photochromic lenses, or on researching the molecular dye used in each lens and form a deep comparison between the material used and the function it serves. Additionally, I would like to try a project that includes reaching out to people and working in a larger team rather than working on an individualized project. I always like to challenge myself in what I don’t feel confident in, so for that reason I would like to enroll in a project that includes more communication and teamwork.

Have you, or do you plan to present this research outside the SOAR presentations? If so, where? Be specific, if possible.

I believe that I will be presenting on Scholar’s Day in the spring term, and to the physics department at some time in the spring semester as well.