Focused on Your Health
Our Doctor Team
Passionate about patient care
From our optometrists to our office staff, the experts at IEC care about you and your health. We are dedicated to delivering a high-quality, comfortable experience with doctors you can trust.
Meet our doctors.
Dr. William Adler
A native of Iowa, Dr. William R. Adler completed his undergraduate degree at Simpson College in Indianola, IA. He received his Doctorate of Optometry Degree from the Illinois College of Optometry in Chicago and began practicing in 1973. Dr. Adler worked for an optometrist in his home town during high school who later talked him into going to Optometry school. After earning his doctorate, Dr. Adler purchased his doctor’s optometric practice. He has been with IEC since 2015. Dr. Adler likes the medical side of Optometry and enjoys interacting with people.
Dr. Daniel Alletto
Dr. Daniel Alletto received his Doctorate of Optometry from Pacific University, Forest Grove, Oregon, where he graduated with distinction. He completed his undergraduate degree at Brigham Young University, Provo, Utah. Dr. Alletto became an optometrist because he loved going to his optometrist’s office when he was growing up. Dr Alletto wants to help his patients see well and have a great experience. He feels rewarded in helping someone see clearly when they expected their vision could never improve. Dr. Alletto particularly enjoys fitting patients in specialty contact lenses, “because I can often take someone’s vision from just being OK to very good.”
Dr. Michael Benedict
Dr. Michael Benedict received his Doctorate of Optometry from Indiana University School of Optometry, Bloomington, IN. He completed his undergraduate schooling from the University of Missouri, Columbia, MO. Dr. Benedict knew he wanted to be an optometrist since high school and began his career as an optometric technician at IEC in Hannibal in 2008.
He followed his passion for caring for patients working with IEC doctors as he completed his Optometric degree and licensure. He began practicing optometry at IEC in 2013. Dr. Benedict’s favorite part is being able to see and treat systemic issues just by viewing the retina.
Dr. Ronald Brand
Dr. Ron Brand was awarded his Doctorate of Optometry from Illinois College of Optometry, Chicago, IL, in 1985. He completed his undergraduate studies at Illinois State University. A native of Peoria, IL, Dr. Brand began practicing optometry at International Eyecare Center in Kirksville, Missouri, in 1985. Dr. Brand’s interest to become an eye doctor began early. “When I was 10, I accompanied my mother to our optometrist for her checkup. He checked her blood pressure and we went from that office directly to her primary care physician, and on to the pharmacy for hypertension medicine. Even at 10, I could tell that optometrists really made a difference.”
Dr. Calvin Daack
Fort Madison Location
Calvin Daack, O.D. received his Doctor of Optometry from the University of Missouri at St. Louis in 2021 and earned his Bachelor of Science in Neuroscience from Drake University in Des Moines, Iowa. His special field of interest is neuro‑optometry.
Dr. Daack believes optometry is an amazing field. It offers him the opportunity to not only educate his patients about their overall eye health, but also advise them on how they can keep their eyes healthy so they can experience their best vision possible every day.
Dr. Daack has a strong desire to help others, and he enjoys meeting new people and getting to know his patients while building connections with them to solve their specific vision needs. Dr. Daack loves seeing his patients’ vision improve with just the right pair of glasses or eye drops.
In his spare time away from the office, Dr. Daack is an avid runner, a martial artist, and a big Iowa Hawkeyes sports fan. His hobbies also include spending time reading and exploring new cities.
Dr. Kaitlin Griffith
Dr. Kaitlin Griffith received her undergraduate degree in biology at Southern Illinois University in Edwardsville, IL. She later earned her Doctorate of Optometry at the Illinois College of Optometry. Dr. Griffith has been practicing since 2014 and joined IEC in September 2019. She always knew she wanted to be in healthcare and finds it fulfilling to be able to help patients see their very best. Dr. Griffith said, “I feel like it’s a medical profession with instant gratification for the patient.” Outside of work, she loves to spend time with her family.
Dr. Tara Guinn
Dr. Tara Guinn earned her undergraduate degree from Iowa State University. She furthered her education by obtaining a Doctorate of Optometry at Midwestern University Arizona College of Optometry graduating with honors. She has been a patient at IEC since 2014 and started practicing at the Kirksville practice in 2020. Dr. Guinn loves getting to work with patients of all ages. She enjoys helping patients see their best with a new pair of glasses or contacts, as well as using the latest technology to optimize treatment and management of ocular conditions while enhancing their overall eye care experience.
Outside of work, she loves raising her children on their family farm, gardening, and playing cards/board games.
Dr. Thomas Johnson
Dr. Thomas Johnson received his Doctorate of Optometry at Southern California College of Optometry in Fullerton, California. An Iowa native, he completed his undergraduate degree at Iowa State University, and achieved a Master’s Degree in Education from the University of Iowa. Dr. Johnson has practiced optometry in Centerville since 1994 and continued when his practice became part of IEC in 2013.
Growing up, Dr. Johnson loved school and was a science nerd. After his military service, he was a science teacher. The GI bill provided the opportunity for him to become an optometrist. Now, Dr. Johnson enjoys seeing his patients in his hometown practice and hearing about their personal stories.
Dr. Austin Krohn
Dr. Austin Krohn received his Doctorate of Optometry from Southern College of Optometry, Memphis, TN. He completed his undergraduate degree in biology from Truman State University in Kirksville, MO. Dr. Krohn is ACMO certified (advanced competency in medical optometry). “The reason I became an optometrist is because I had a higher prescription as a child. Getting glasses and contact lenses made a huge difference in my school and athletic careers. I like fixing problems. I enjoy determining the cause, finding the solutions, and figuring out which solution would work best for each individual. It’s rewarding knowing that when we do a good job, it impacts literally every day of that patient’s life whether they know it or not.”
Dr. Tim Leahy
Dr. Tim Leahy completed his undergraduate degree from Augustana College in Rock Island, IL. He received his Doctorate of Optometry from Illinois College of Optometry in 1993, graduating cum laude. He joined International Eyecare Center the same year.
Growing up, he had a great optometrist who opened the door to a career in optometry. Dr. Leahy truly enjoys helping people see better and is pleased that he chose a career that allows him time to spend with his family.
Dr. Jason McDowell
Dr. Jason McDowell earned his Doctorate in Optometry from the University of Missouri School of Optometry in 1998. He attended Hannibal LaGrange University, Hannibal, MO for his undergraduate work. Dr. McDowell began practicing optometry in the Hannibal-Quincy area prior to joining IEC in Jacksonville in 2001.
Dr. McDowell had an eye problem in the 9th grade, and his entire experience sparked his interest in becoming an eye doctor. He enjoys getting to know his patients and helping them to see well.
Dr. Elizabeth Monroe
Dr. Elizabeth Monroe received her Doctorate of Optometry at Indiana University School of Optometry, Bloomington, IN. She graduated Cum Laude from Southern Illinois University-Carbondale with a degree in physiology. “I always knew I wanted to do something in the medical profession; I wanted to help people live their best life. When I discovered optometry, I knew it was the right fit for me. The most rewarding part of being an optometrist is helping people see the world in a new way. It’s truly amazing to help a patient see road signs again or be able to read their favorite book. It can change a person’s life and I love that I can be a part of that.”
Dr. Kenneth Mueller
Dr. Ken Mueller earned his undergraduate degree from Millikin University in Decatur, IL, graduating Magna Cum Laude. He joined IEC after receiving his Doctor of Optometry from Indiana University in 1990 where he earned recognition for his original research in the area of contact lenses. After deciding to become a doctor, he changed his focus from surgery to optometry. Being in a small community, really knowing his patients and their families, and being able to serve their eyecare needs is meaningful to Dr. Mueller. He finds optometry tremendously rewarding, being on the forefront of medical care and technology for his glaucoma and macular degeneration patients and helping to ensure their good vision for a lifetime.
Dr. Tyler Page
Dr. Tyler Page was born and raised in southern Utah. He has a Bachelor of Science in Biology with a concentration in Zoology from Southern Utah University. Dr. Page has always been fascinated by the eye, so naturally, optometry was the perfect fit for him. He loved the idea of being in the healthcare industry and helping people improve their lives. Dr. Page is a highly experienced optometrist who specializes in Dry Eye and Ocular Diseases so he can contribute to his patients’ quality of life through preserving and enhancing their vision.
Growing up in a small town in Utah, Dr. Page learned to appreciate the outdoors. Activities such as fishing, camping, and spending time outside with friends and family was – and still continues to be – a major part of his life. Dr. Page met his wife in Ames, Iowa while at Iowa State University; together they have five beautiful kids who keep them very busy. In his spare time, Dr. Page enjoys playing and watching sports, and even coaching a youth soccer team.
Dr. Jonathon Thoele
Dr. Jonathon Thoele completed his undergraduate degree at Quincy University and received his Doctorate of Optometry from Illinois College of Optometry, Chicago, IL. He began practicing optometry at IEC in 2012.
Dr. Thoele finds optometry to be a “family friendly” career choice. One of his favorite parts of his profession is when a child gets excited to be seeing clearly with new glasses for the first time in his/her life.
Dr. Ryan Thoele
Dr. Ryan Thoele graduated from Quincy University with his undergraduate degree in biological sciences. He earned his Doctorate of Optometry Degree at the Illinois College of Optometry in Chicago, IL. After completing his residency in 2012, Dr. Thoele joined IEC to begin practicing optometry. He finds the most rewarding part of being an optometrist is to provide the proper spectacle correction for his patients, especially children, and then be able to witness their first reaction to seeing clearly.
Dr. Abby Thomas
Dr. Abby Thomas practiced optometry for seven years in a busy ophthalmology and optometry practice in Davenport, IA. Her areas of specialty include: the fitting of contact lenses, the treatment of eye disease and pediatric vision care. She will provide low vision examinations, prescribe devices and provide experience in training the visually impaired. Dr. Thomas received her Doctorate of Optometry from Illinois College of Optometry, Chicago, IL in 2006 and was a recipient of the Corning Low Vision Award. She completed her residency in ocular disease and low vision at South Arizona VA Health Care System and Southwest Blind Rehabilitation Center. A native of Ft. Madison, IA, Dr. Thomas received her bachelor’s degree in psychology from Iowa State University. Along with general eyecare, Dr. Thomas also treats patients with: glaucoma, diabetes, dry eye syndrome, macular degeneration, multifocal and specialty contact lens fitting, and pediatric eye health.
Dr. Derek Vogelpohl
Dr. Derek Vogelpohl received his Doctorate of Optometry from Illinois College of Optometry, Chicago, IL, Summa Cum Laude and Salutatorian of his class. He earned his undergraduate degree in Chemistry at the University of Illinois, Urbana-Champaign. Dr. Vogelpohl worked at IEC as an optometric technician during college; he began his optometric career at IEC in 2013.
His favorite part of optometry is getting to know his patients and helping them to preserve and maintain their vision and eye health.