Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.

The healthcare system is constantly changing and complex. Various services are available from different healthcare providers, but gaining access to these services has become challenging for people with limited healthcare insurance. Uninsured people present a challenge to healthcare because they frequently postpone or forego treatment.
The Institute of Medicine (IOM) advocates for a patient-centered, effective, safe, timely, equitable, and effective healthcare system. The National Priorities...

Nursing involves independent, cooperative, person-centered care for people of all ages, families, groups, and communities. Nurses assist the sick or the well person in all settings. Nursing includes promoting health, preventing illness, and caring for ill, disabled, and dying people. Health promotion encourages people to take responsibility for their health. It focuses on the healthy behavior of individuals, families, and the community and the factors that impact their health. Examples of...

Primary care promotes wellness and prevents disease. This care includes health promotion, education, protection (such as immunizations), early disease screening, and environmental considerations. Settings providing this type of healthcare include physician offices, public health clinics, school nursing, and community health nursing.
In 1978, international leaders convened in Alma-Ata, Kazakhstan, for what would be a pivotal event in global health. The Alma-Ata Declaration was the first to call...

Secondary healthcare is offered by a specialist, generally in hospitals or clinics for patients referred by primary healthcare providers. It occurs when a person has an illness or injury that requires specific medical care. Secondary care is often referred to as acute care. Secondary care can range from uncomplicated care to repair a minor laceration or treat a strep throat infection to more complicated emergent care, such as treating a head injury sustained in an automobile accident. Whatever...

At the different levels of the healthcare system, we see varying methods of healthcare used. These methods include managed care systems, case management, and primary healthcare.
Managed Care System:
The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is limited...