Are you worried about being "politically correct" when talking to someone with a disability? Are you afraid you might inadvertently offend a disabled person? If so, you are not alone. Disability is a broad term. It can mean a physical condition, a mental condition or a learning disability such as dyslexia (which is my own disability; thank goodness for my editor!).
In any of these cases, it's important to know how to relate to anyone with a disability. When writing or speaking about people with disabilities, emphasize their abilities rather than their disabilities. Never define people by their disabilities.
When you meet or see someone with a physical disability, the first rule is don't stare. Treat all disabled people as you would want to be treated if you have the same condition. A friend of mine who has Stargardt disease, the inherited childhood-onset version of macular degeneration, says her main complaints are "people who think that if I cannot see, I cannot hear; people who infantilize their dialogue thinking that if I cannot see, I must be stupid; and people who argue with me when I do ask for help ('Why don't you wear glasses?')." Try to put yourself in the disabled person's shoes and think about how you would want others to relate to you.
Avoid asking personal questions about someone's disability. It is appropriate to extend your hand when being introduced to a person with a disability, even if he or she has an artificial limb. If the person cannot shake hands, a touch on the shoulder or arm is okay. Look and speak directly to the person with a disability, not to their companion or interpreter.
Even if you see that a person is wearing a hearing device, don't raise your voice unless requested.
Be willing to repeat or rephrase a question if the disabled person you're speaking to doesn't understand you. Use patience. If someone is using a cane or crutches or is in a wheelchair, take care not to get in their way or walk too close to them.
It's okay to ask, "Can I help you with the door?" or "Can I give you a hand?" if you think it might be needed.
If you know a person has a visual impairment, and you think he or she might need help, don't just grab the person's arm. First, identify yourself, then ask if he or she would like to take your arm. Then, describe the location in specific terms, so the person will know exactly what the terrain is like, or what the barriers or parameters are. Never pet or distract a guide dog.
Remember that it's not always easy to tell if a person is disabled or what a disability might be. If a person behaves oddly, you should always consider the fact that they may have a disability that is not immediately obvious and then treat them accordingly.