Primary glaucoma is characterized by what type of vision loss?

Primary glaucoma is primarily characterized by the loss of peripheral vision. This condition often progresses gradually, leading to what is commonly referred to as "tunnel vision," where the individual retains central vision but experiences a narrowing of their overall visual field.

The pathology of glaucoma involves increased intraocular pressure that can damage the optic nerve, leading to this specific type of vision loss. As the disease advances, individuals may become increasingly unaware of their peripheral surroundings.

In terms of other types of vision loss mentioned in the options, the loss of color vision is more indicative of retinal problems or optic nerve issues rather than glaucoma. Central vision loss is typically associated with macular degeneration rather than glaucoma. Double vision, or diplopia, generally relates to issues with cranial nerves, muscle imbalances, or other neurological conditions, which do not directly correlate with the mechanisms of glaucoma. Thus, the correct identification of peripheral vision loss in primary glaucoma is crucial for understanding its clinical presentation and progression.