Both bacterial and viral eye infections are contagious (usually from person to person). The only way to tell the difference between bacterial and viral eye infections is an eye exam from an ophthalmologist.
Most eye infections are viral, and are very infectious.
Bacterial eye infections are less common and are treated with antibiotic drops and pills, and treatment of the underlying cause, such as chronic blepharitis or lid infection.
Viral eye infections are treated with artificial tears, mild steroid drops, and drops to prevent redness and itching. Special care is necessary to avoid giving the infection to others, including careful hand washing, throwing away eye make-up and contaminated contact lenses, and trying not to rub the eyes.
Be careful of "persistent" or "chronic" eye infections — they may be something else entirely, such as chronic inflammation from blepharitis or dry eye.
Don't stay on steroid drops for more than a few weeks. I just saw a patient who had been treated with steroid eye drops for a chronic lid infection from his primary care doctor. The patient wasn't getting better, so he kept re-filling the prescription, and after six weeks of (ineffective) treatment, he had steroid induced glaucoma in both eyes (and a stye which wouldn't go away)
Although there is no cure for dementia at present, if it's diagnosed in the early stages, there are ways you can slow it down and maintain mental function. A diagnosis can help people with dementia get the right treatment and support, and help those close to them to prepare and plan for the future. With treatment and support, many people are able to lead active, fulfilled lives. The symptoms of dementia tend to worsen with time. In the much later stages of dementia, people will be able to do far less for themselves and may lose much of their ability to communicate. Read more about how dementia is diagnosed, or find out more about: Living with dementia Staying independent if you have dementia Looking after a loved one with dementia