Full Definition of COLLECTIVE. 1. 2. a: formed by collecting: aggregated b of a fruit: multiple. 3. a: of, relating to, or being a group of individuals. 4. : marked by similarity among or with the members of a group.5. : collectivized or characterized by collectivism.ull Definition of COLLECTIVE. 1. : a collective body: group. 2. : a cooperative unit or organization; specifically: collective farm. 3. : a helicopter control system governing lift. See collective defined for English-language learners.
Listen. The most common vision problems are refractive errors, more commonly known as nearsightedness, farsightedness, astigmatism and presbyopia. Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina.ision occurs when light rays are bent (refracted) as they pass through the cornea and the lens. The light is then focused on the retina. The retina converts the light-rays into messages that are sent through the optic nerve to the brain. The brain interprets these messages into the images we see.
The shrinking vitreous can pull on the retina as it detaches, stimulating the nerves and causing light flashes. PVD is the most common cause of the sudden appearance of eye light flashes, occurring in roughly 50 percent of people with the condition. Floaters also occur frequently with PVD. Despite the rather scary name, PVD is a common age-related eye change that typically develops after age 60. People who are nearsighted have an increased risk for the condition. Vision loss rarely occurs with PVD and the light flashes usually disappear within 1 to 3 months.