Abnormal, harmful, or undesirable effect on an organism that causes anatomical or functional damage, irreversible physical changes, or increases the susceptibility to other biological, chemical, or environmental stresses.
Optometrists can prescribe glasses, contact lenses, eye exercises, vision aids and therapy, and (in some states) oral and topical medications to treat certain eye diseases. Ophthalmologists are doctors of the eye. They have graduated from medical school and are licensed to practice medicine, so their credentials are either doctor of medicine (MD) or doctor of osteopathy (DO).
I think doctors can prescribe thereself with medication but then again I'm not so sure.. Another doctor might have to do it. I think doctors can prescribe medications for themselves except there's checks to make sure they are not abusing substances. So yes they can. If need be they just prescribe for eachother, I've seen a doctor prescribe for the daughter of another doctor (who wasn't their patient)....