Optometry and audiology are somewhat analogous professions in the scope of vision and hearing care. They have similar roles in the hierarchy of ophthalmologist-otolaryngologist and opticians-hearing instrument specialists. Optometrists, however, have recognition as limited license physicians (LLP), limited prescription rights, and some surgical authority. Let’s dig in deeper and learn more about optometry.

Comparing the Professions

From our quick snapshot in TABLE 1, it is clear that optometry has been around as an independent profession for much longer and is a little over three times larger in labor force. The differential in labor force is intriguing given that hearing loss has a higher prevalence than vision loss with age (i.e., 26 percent of older adults have hearing loss versus 15 percent with vision loss [NCHS, 2010]).

Education 

The years of education are comparable and there is no requirement for post-graduate residency, though options exist within optometry. Unlike audiology, optometry maintains its own entrance and national board examinations. The optometry entrance exam called the Optometry Admissions Test has four parts: natural sciences (including biology, general chemistry, and organic chemistry), physics, reading comprehension, and quantitative reasoning. However, most audiology programs use the general record examination (GRE) as part of their admission process. The general GRE test is comprised of analytical writing, verbal reasoning, and quantitative reasoning. There is no science component, unless a program requires a GRE Subject Test in a specific area. 

Audiology and optometry licensure are contingent upon passing a national exam. Currently, for audiology this is the Praxis examination in audiology facilitated by the educational testing service (ETS). The Praxis test series are generally used to assess knowledge for teaching. Optometry licensure is contingent upon passing the National Board of Examiners in optometry exams. This is a three-part exam generally taken over years three and four of the optometry program. There are also special examinations required depending on state scope of practice.

TABLE 1. Quick Snap Shot *2014 Bureau of Labor Statistics The breakdown of practice setting and revenue were derived from the “The State of the Optometric Profession: 2013” report and ASHA/AAA survey reports and represent approximations.

  AUDIOLOGY OPTOMETRY
Current Labor Force* 13,000 40,0000
Median Pay* $76,000 $106,000
Average Age 44.9 years 46 years
% Male/Female (Approx.) 20%/80% 60%/40%
State Licensure Est. (year) 1969 1901
First Clinical Doctor of Degree Awarded (AuD or OD) 1996; Baylor 1923; Pennsylvania College of Optometry
Pre-Entrance Requirements Some programs require communications sciences and disorders degree or course work; common prerequisites: life science, physical science, behavioral science, statistics Pre-optometry (non-degree program); common prerequisites: English, calculus, statistics, biology with lab, inorganic chemistry with lab, organic chemistry with lab, physics with lab, psychology
Entry Exam Graduate Record Examination Optometry Admission Test
National Board Exam Praxis National Board of Examiners in Optometry—three-part exam over four years
Accreditation Body Council on Academic Accreditation; Accreditation Commission for Audiology Education Accreditation Council on Optometric Education
Years of Education 3-4 4
Number of Programs 74 23
CMS Status Other Diagnostic  Limited Licensed Physician since 1986
Post-Graduate Residency None Optional 1-2 year in various sub-specialties
First Prescription Fights (year and state) None 1971; Rhode Island
50th Prescription Rights (year and state) None 1997; Massachusetts; DC in 1998
Surgical Limited Rights (year and state) None 1998; therapeutic laser in Oklahoma
Independent Private Practice 21% 57%
Big Box or Chain 6% 24%
Otolaryngology or Ophthalmology Practice 27% 8%
Other Practice (e.g., hospital, VA, etc.) 46% 11%
Principle Revenue Sources Diagnostics and hearing aid dispensing Eye examinations and sale of corrective devices
Average Revenue Per Diagnostic Exam (per hour) Not available $306
Average Sale for Devices (not revenue) $2,347 average hearing aid retail sale price $227 glasses and $152 contact lenses

Law and Scope of Practice

State licensure law dictates scope of practice. While audiology does not maintain pharmaceutical prescription rights, optometry does have limited prescriptive privileges. Interestingly, it took optometry over 70 years after initial state licensure laws to establish its first state with prescription rights, and over 25 years for the profession to have prescription rights adopted by all 50 states. In most states, optometrists are limited to topical medications and limited oral drugs such as short-duration antibiotics, antihistamines, and analgesics.

The field of optometry has been more successful than most non-MD professions in expanding their scope of practice. Psychologists have been trying for almost 30 years to win prescription privileges, so far only two states have granted this expansion (Louisiana and New Mexico). Podiatrists have faced significant resistance from medical and orthopedic associations to include the ankle under their scope of practice. Despite the successes of optometry regarding scope of practice expansion, the process has been slow. In addition to the previously mentioned time period for garnering prescription rights, securing surgical privileges has also been a challenge. This was first awarded in Oklahoma in 1988. The profession of optometry then had to wait nine additional years to get very limited privileges in a second state (New Mexico).

Practice Setting and Salary

Practice setting is also significantly different between the two professions. The majority of optometrists work in private practice or in franchise practices. Audiologists, on the other hand, have a larger footprint in hospitals, residential health facilities, and in non-audiologist owned practices (e.g., ENT-owned). Both audiologists and optometrists derive the majority of their revenue from diagnostic evaluations and device sales. 

The higher abundance of private practice and expanded scope of practice with LLP status (e.g., pharmaceutical and surgical privileges) for optometry likely reflect the contrast in median salary compared to audiology. However, the gender profile of each profession may also be a factor. This does not dictate discrimination or view of audiology as a lesser profession due to larger female prevalence. Indeed, the separation in median salary remains even when stratified by sex. 

A survey by the American Optometric Association (AOA) in 2011 found median income for female optometrists was $103,500 and $131,000 for male optometrists: women were earning 77 percent of men’s earnings. In this same survey, males reported working almost 200 more hours per year and, among females, nearly 50 percent were new practitioners (less than 10 years) compared to 26 percent of males. 

After accounting for these variables, the female-to-male annual earnings ratio was over 95 percent. The American Academy of Audiology’s (the Academy) compensation and benefits survey from the same year showed males with a median salary of $95,000 and females $73,000, with a comparable female-to-male earning ratio of 77 percent.
Similar to optometry, only 24 percent of the males surveyed had less than 10 years of experience, while 39 percent of females had less. Independent of gender, salary contrast remains. The audiologist to optometrist earnings ratio is 70–72 percent for both males and females. Claudia Goldin, an expert in gender pay gap has suggested the largest factor in gender pay disparity is “temporal flexibility” with minimal impact of outright discrimination, competitive drive, or bargaining ability (though these can be factors). Temporal flexibility refers to greater flexibility in work hours, work schedule, etc. (Goldin 2014).
This begs the question, is it possible that temporal flexibility underlies the wage gap for audiologists and optometrists? Would greater emphasis and support for private practice ownership close this gap?

Disruptive Innovation

Audiology and optometry also have a common concerns for disruptive innovations. A primary concern voiced by audiologists on many social media platforms is the potential loss of revenue due to over-the-counter (OTC) amplification threats. Over-the-counter glasses or non-prescription reading glasses, however, have existed for many decades, and the revenue derived from prescription corrective lenses remains strong. 

Optometry is not immune to disruptive innovation. Online eye exams and prescriptions bypassing a traditional visit to the eye doctor are available and creating a stir. For example, Opernative offers an online refractive eye test and prescription glasses.

Other disruptive players include EyeNetra and Warby Parker. Eyenetra is a smartphone-based vision diagnostic tool that allows for accurate self-administered refraction results and prescriptions. Eyenetra can also be used by optometrists to enable remote testing or mobile clinic services. Comparable efforts in audiology are SHOEBOXTM audiometry.

Warby Parker is like an Apple store for glasses. With a focus on designing and creating frames and a commitment to user experience, they upended the traditional market which is dominated by a single company that makes most of the eyeware that exists in the world. Warby Parker also has a socially conscious platform where they donate a pair of glasses to VisionSpring for every pair sold. This is a fairly common market strategy in audiology; numerous companies manufacture hearing aids and it is common for manufacturers to have their own private label platform and have philanthropic aims. 

Another interesting innovation is self-adjusting glasses. Joshua Silver, a physics professor at the University of Oxford in England, has created self-adjusted glasses using silicon oil. He hopes to sell them for $1 a pair. They are currently sold for $19. Lower cost, self-adjusted hearing aids or personal sound amplification technology exists and will soon expand in the United States with recent passage of the Over-the-Counter Hearing Aid Act. Though something of quality at $1 a pair is not likely.

Medicine and Disruption

Audiology and optometry are not the only fields that are being disrupted. Medicine is under constant pressure from non-physician groups for expansion of service. Most disruptions have a general trend for simplification to disrupt complexities (Christensen et al, 2000). The greatest threat physicians face is that the vast majority of existing data demonstrate no significant difference between mid-level care provided by a physician and a non-physician, e.g., nurse practitioner (Isaacs and Jellinek, 2012). 

Data to this effect can also be found for audiology. Zapala et al (2010) examined over 1,500 records of Medicare-eligible patients seen at the Mayo Clinic in Florida. The records seen jointly by audiology and otolaryngology (n=352) were reviewed by four blinded reviewers (two otolaryngologists and two audiologists) to judge if the audiologist treatment plan would have missed a medical condition. Records of patients seen by audiology only (n=1,198) were reviewed by a neuro-otologist who judged if a referral would be recommended based on the test results. 

The results showed there was no discrepancy in treatment plans for over 95 percent of cases. In no case did an audiologist miss a condition associated with significant mortality or morbidity. The neuro-otologist reviewing the second set of cases found that only audiology services were needed in nearly 80 percent of the cases. Further, there was strong evidence that audiologists referred to otolaryngology when appropriate.

Conclusion

Audiology and optometry have many similarities and face comparable disruptive forces. Optometry has been more successful in securing their scope of practice and up-marketing their profession. In other words, through greater internal control (e.g., specialty admission and board exams), securing LLP status, and expanding their scope of practice, they have disrupted those “above” them (i.e., opthamology) rather than fight a reactionary and likely futile battle with disrupters from below (e.g., OTC devices). 

Disruptions are inevitable and the general trend is for simplification to disrupt complexities (Christensen et al, 2000). What remains to be seen is if audiology will be the disruptors or the disrupted.