What can an optometrist do that an ophthalmologist cannot?

September 22, 2025 •

4 min read

According to the American Optometric Association, optometrists provide over two-thirds of primary eye care in the U.S.. This highlights the crucial role they play in routine vision health. While an ophthalmologist is a medical doctor who can perform most optometric functions, understanding what can an optometrist do that an ophthalmologist cannot truly hinges on specialization and standard practice.

Quick Summary

Optometrists provide primary eye care, fitting complex contact lenses, conducting routine exams, and delivering vision therapy, which ophthalmologists typically focus less on or refer out due to their surgical specialization.

Key Points

Advanced Contact Lens Fitting: Optometrists are the experts in fitting specialized and complex contact lenses for unique conditions like keratoconus, a service ophthalmologists typically refer out.
Vision Therapy: An individualized program managed by an optometrist to correct eye alignment and coordination problems, which is outside the standard practice of surgical ophthalmology.
Primary Care Focus: As the primary vision care provider, an optometrist spends a greater portion of their practice on routine exams and diagnosing common, non-surgical eye issues, serving as the first point of contact for patients.
Low Vision Rehabilitation: Optometrists specialize in assisting patients with irreversible vision loss by prescribing custom optical aids and developing rehabilitation strategies to maximize functional sight.
Pre- and Post-operative Care: For patients undergoing eye surgery by an ophthalmologist, the optometrist often handles the extensive pre- and post-operative management, ensuring seamless patient care.
Broad Training on Refractive Conditions: The core of an optometrist's training is rooted in vision correction, making them the most practical choice for routine needs like updated glasses or contact lens prescriptions.

The Core Difference: Primary vs. Specialty Care

The fundamental distinction between an optometrist and an ophthalmologist is their primary focus and scope of practice, which is shaped by their respective education. An optometrist holds a Doctor of Optometry (OD) degree and specializes in primary vision care, performing routine eye exams, prescribing corrective lenses, and diagnosing common eye conditions. An ophthalmologist is a medical doctor (MD or DO) who completes medical school plus an intensive residency focused on surgical and advanced medical eye care. While an ophthalmologist technically possesses the training to perform all optometric functions, their practice is concentrated on surgery and the treatment of complex diseases, leaving many routine services to optometrists. The question isn't so much what an optometrist is exclusively licensed to do, but rather what they specialize in and are the go-to experts for in standard practice.

Optometrists as Primary Eye Care Providers

For the vast majority of eye care needs, the optometrist is the frontline practitioner. They are expertly trained to handle comprehensive eye exams and manage non-surgical conditions. This includes:

Refractive Care: The main purpose of many eye exams is to determine a patient’s refractive error (nearsightedness, farsightedness, or astigmatism) and prescribe the appropriate corrective lenses, including eyeglasses and standard contact lenses. While ophthalmologists can also do this, it is an optometrist's bread and butter.
Initial Diagnosis and Triage: Optometrists are highly skilled at detecting a wide range of eye and vision problems during a routine exam. They can identify the early signs of more serious eye diseases like glaucoma, cataracts, and diabetic retinopathy, and then refer the patient to an ophthalmologist for advanced treatment or surgery. They act as the initial gatekeeper for more specialized care.
Management of Common Eye Conditions: Optometrists regularly diagnose and treat common eye conditions such as dry eye, conjunctivitis (pink eye), and allergic reactions affecting the eyes. They can prescribe necessary topical medications for these non-surgical issues.

The Specialization of Vision Therapy and Rehabilitation

One area where optometrists truly distinguish themselves is in specialized vision services that are not typically the focus of an ophthalmologist's surgical practice. These include vision therapy and low vision rehabilitation.

Vision Therapy

This is a non-surgical, individualized program designed to treat a variety of vision problems that go beyond simple corrective lenses. A patient might work with an optometrist for conditions such as:

Amblyopia (Lazy Eye): A weakening of vision in one eye due to poor communication between the brain and the eye. Optometrists use therapy to improve this connection.
Strabismus (Crossed Eyes): Misaligned eyes can be improved with vision therapy to retrain the eyes to work together correctly.
Accommodative or Binocular Vision Dysfunction: These are issues related to focusing and eye teaming that can cause eye strain, headaches, and reading difficulties. An optometrist provides tailored exercises to correct these problems.

Low Vision Rehabilitation

For patients with permanent vision loss that cannot be corrected with traditional glasses or contacts, optometrists provide rehabilitative services. This involves prescribing specialized low vision aids, such as magnifiers, telescopes, and adaptive technologies, to help people maximize their remaining vision and maintain independence.

Advanced Contact Lens Fitting

While ophthalmologists can write contact lens prescriptions, optometrists are often the experts in fitting specialty contact lenses. This is especially true for patients who require custom solutions due to unique eye conditions or post-surgical needs. These specialized fittings include:

Corneal Transplants: Following a corneal transplant, the eye's shape changes, necessitating a customized lens fitting that an optometrist is highly skilled in providing.
Keratoconus: This condition causes a cone-shaped cornea. Optometrists use specialized rigid gas-permeable (RGP) or scleral lenses to correct vision in a way that standard ophthalmological practice rarely focuses on.
Other Complex Irregular Corneas: Optometrists possess the expertise and dedicated chair time to work with patients who cannot wear conventional contact lenses due to complex corneal shapes.

Collaboration is Key

In many cases, an optometrist and ophthalmologist work together to provide comprehensive care. The optometrist serves as the primary eye care provider, and should they detect a condition requiring surgical or highly specialized medical intervention, they refer the patient to an ophthalmologist. Post-surgery, the patient is often referred back to the optometrist for follow-up and long-term management. This collaborative model ensures the patient receives the best of both worlds: specialized expertise for complex conditions and dedicated, routine care for ongoing vision health.

Optometrist vs. Ophthalmologist: A Comparison


Feature	Optometrist (OD)	Ophthalmologist (MD/DO)
Training	4-year optometry school post-undergrad	4 years medical school + 4 years residency post-undergrad
Degree	Doctor of Optometry (OD)	Medical Doctor (MD) or Doctor of Osteopathy (DO)
Core Focus	Primary vision care, vision correction, diagnosing and managing common eye conditions	Surgical procedures and treatment of complex eye diseases and trauma
Key Specialties	Refractive care, advanced contact lens fitting, vision therapy, low vision rehabilitation	Cataract surgery, LASIK, glaucoma surgery, retinal procedures, oculoplastics
Procedures	Prescription of lenses, minor foreign body removal, in-office procedures (state-dependent)	All eye surgery, advanced diagnostics, systemic disease management
Typical Role	First point of contact, routine exams, long-term vision management	Specialized surgeon and medical consultant, often for referral cases

Conclusion: Understanding the Roles

The idea that an optometrist can do something an ophthalmologist cannot is a misnomer, as the broader medical training of an ophthalmologist covers the full spectrum of eye care. The real distinction lies in their specialization and day-to-day focus. While an ophthalmologist is a medical-surgical specialist, an optometrist focuses on the non-surgical aspects of vision correction and primary eye health. The unique services an optometrist provides, such as advanced contact lens fitting and vision therapy, are functions that an ophthalmologist typically does not specialize in, nor have the time for. Knowing these differences is key to choosing the right professional for your specific eye care needs and navigating the collaborative ecosystem of vision health. For more on the scope of eye care practices, visit the American Academy of Ophthalmology.

Frequently Asked Questions

Technically, yes, because an ophthalmologist is a medical doctor with a broader scope of practice that includes surgical training. However, in practice, their time is focused on surgery and advanced medical care, so they typically do not specialize in or perform the routine services that are the focus of an optometrist’s practice.

Vision therapy is a customized, non-surgical program, often provided by an optometrist, to treat visual problems that interfere with learning, reading, and sports performance. It involves a series of exercises to improve eye coordination and focusing skills.

Yes, in many jurisdictions, optometrists are licensed to diagnose and medically manage glaucoma using prescribed medications. They will often co-manage the patient's care with an ophthalmologist, particularly in more advanced cases.

You should generally see an optometrist for routine eye exams, updated prescriptions for glasses or contacts, and the treatment of common eye conditions like dry eye or conjunctivitis. They are your primary eye care provider.

Yes, optometrists can prescribe a range of topical and, in some states, oral medications for treating eye conditions and infections. The specific scope of prescribing authority varies by state.

A specialty contact lens fitting is a service provided by optometrists for patients who cannot wear conventional contact lenses. This is common for patients with irregularly shaped corneas due to conditions like keratoconus or those who have had a corneal transplant.

No, optometrists do not perform eye surgery. In the event a surgical procedure is necessary, they will refer the patient to an ophthalmologist. Optometrists may, however, handle pre- and post-operative care related to the surgery.

It is common for the two professions to work collaboratively. An optometrist might act as the initial point of contact, diagnosing issues and providing routine care. If a surgical or highly complex medical issue is detected, they refer the patient to an ophthalmologist for specialized treatment. Post-surgery, the patient may return to the optometrist for ongoing management.