How do tropicamide drops improve vision?

Dilate drops: Only by dilating the pupils to allow more light to enter.

It can: Tropicamide is a dilating drop, which means it makes your pupil larger, allowing more light in. If you have a corneal or lens condition (scars or certain kinds of cataracts) that affects the center of your vision, dilating your pupil may allow you to see around the blockage (opacity), improving you vision. This is especially true for people with a posterior subcapsular cataract.

Not usually: Tropicamide is used to dilate the eyes for an examination. If you have a central cataract, or need amblyopia treatment, then dilating drops can sometimes improve vision but other lonbger acting ones work better than tropicamide.