Which condition primarily affects a student's ability to adapt from light to dark?

The correct condition that primarily affects a student's ability to adapt from light to dark is retinitis pigmentosa. This genetic disorder leads to a gradual degeneration of photoreceptor cells in the retina, particularly affecting rod cells that are responsible for night vision and adaptation to low-light conditions.

As the rod cells deteriorate, individuals may experience difficulty seeing in dim light and may struggle to transition smoothly from well-lit areas to darker environments. This impairment significantly impacts their ability to adjust to changing light levels, leading to challenges in situations like moving from outside sunlight into a darker room.

Cataracts can lead to overall decreased vision and problems with glare but do not specifically hinder the adaptation mechanism from light to dark. Similarly, macular degeneration primarily affects central vision and visual acuity rather than light adaptation. Glaucoma affects peripheral vision and can cause other visual disturbances, but it does not primarily disrupt the ability to adapt to light changes like retinitis pigmentosa does.