Charles Knowles, O.D.
Charles Knowles, O.D. is a provider specialising in Corneal and Contact Management Optometrist in Fort Worth, TX, registered under NPI 1407985880. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 309 S OAKLAND BLVD, Fort Worth, TX 76103. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 3132T | TX | Corneal and Contact Management Optometrist primary |
This provider holds licence 3132T issued in TX. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Optometry
- PAC ID
- 9931511755
Medicare enrolment is recorded as approved under the provider type Practitioner - Optometry. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Corneal and Contact Management covers
The professional activities performed by an Optometrist related to the fitting of contact lenses to an eye, ongoing evaluation of the cornea's ability to sustain successful contact lens wear, and treatment of any external eye or corneal condition which can affect contact lens wear. NUCC Health Care Provider Taxonomy, code 152WC0802X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1407985880 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 3, 2007 |
| Last updated | Dec 11, 2020 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | O.D. |
| Practice address |
309 S OAKLAND BLVD Fort Worth, TX 76103 (817) 536-9970 Fax (817) 531-2534 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 4 | 0 | 7 | 9 | 8 | 5 | 8 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 0 | 7 | 9 | 8 | 1 | 8 | 7 |
Sum = 70 · next multiple of 10 = 70 · check digit = 0 · actual last digit = 0
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.