Final answer:
The sudden loss of vision in a patient with a retinal tear is most likely caused by retinal detachment, which requires prompt laser treatment. Parallel laser light is used for precision in restoring the retina's proper position. Option C.
Step-by-step explanation:
The cause of sudden loss of vision in a patient with a retinal tear is most likely retinal detachment. Retinal detachment occurs when the retina becomes separated from its underlying supportive tissue. Without prompt treatment, retinal detachment can lead to permanent vision loss. It is important for a retinal tear to be addressed with a medical procedure often involving laser treatment. In this treatment, laser light is precisely focused on the retina to create scar tissue that helps secure the retina in place. The procedure requires the rays entering the relaxed, normal-vision eye to be parallel to achieve accurate focusing and prevent further damage.
It is important to note that while age-related macular degeneration (AMD) is a common cause of blindness due to the death of the macular cells, it is not associated with the sudden loss of vision that occurs with a retinal tear. Meanwhile, cataracts are responsible for a significant proportion of blindness cases due to cloudiness in the eye's lens, but they typically cause a gradual loss of vision, not a sudden one.