What visual deficit is indicated for an older adult who has experienced significant functional vision loss and misidentifies objects in bright light?

Significant functional vision loss accompanied by misidentifying objects in bright light is indicative of cataracts. Cataracts involve the clouding of the eye's natural lens, leading to visual impairment that can be especially pronounced in bright conditions. This clouding scatters light and causes glare, which can make it difficult for individuals to see clearly and can result in misidentification of objects.

In contrast, while macular degeneration can lead to central vision loss and may affect object recognition, it typically does not present with issues specifically tied to bright light conditions. Glaucoma primarily affects peripheral vision and may lead to tunnel vision, while diabetic retinopathy affects the retina and can lead to varying degrees of vision loss but typically does not specifically cause misidentifying objects in bright light as cataracts do. Therefore, cataracts are most closely aligned with the symptoms described in the scenario, making it the appropriate answer.