Federal guidelines require all commercial drivers to pass a DOT health exam

The goal of this exam is to determine whether a potential driver is physically capable of driving safely at the present time as well as in the foreseeable future. 

Department of Transportation Requirements

To pass the physical for the CDL you:.

• With or without vision corrections, each eye, as well as both eyes combined, need to have 20/40 vision.
• Must be capable of distinguishing colors found on traffic signals.
• Hearing should be good enough to notice a forced whisper at a minimum distance of 5 feet.
• An applicant can have diabetes which is controlled through diet or medication. Diabetes which is controlled though insulin injections is not permitted
• Blood sugar may not be higher than 200.
• No use of a Schedule 1 drug, amphetamine, narcotic or any habit forming drug is allowed.
• In case you are currently diagnosed with a cardiovascular disease such as congestive cardiac failure, collapse or cardiac insufficiency, then you will need to provide the Medical Examiner with a stress test along with a note from your physician which states that you are able to drive a commercial motor vehicle without restrictions restrictions.

Content courtesy of dmv.com. For additional information on Texas DOT requirements, visit:
https://www.dps.texas.gov/DriverLicense/medCertReq.htm