Are they totally blind, or low vision? What are their interests?

Something like Bop-It might be good. Not sure if they can count at match numbers at that age, maybe dominos with raised bumps. Things like plush toys are pretty standard.

Check out wonderbaby.Org for a helpful website for blind and visually impaired children, they have some nice idea. You want to stimulate the other senses, touch smell etc. My son has cvi and lights are stimulating to him. Wiki sticks are another good toy for creating 3D drawings

$1 has a nice series of children's books that are Braille and print with shapes, animals, etc.

Learning Palace has a store online and it's fantastic. The 3 year old I nanny for who has very low vision loves the spinning, colorful toys like magnets. There's also great toys for fine motor skills like a squishy pogo stick. He also enjoys the educational games that focus on matching objects to pictures, counting, shapes, and colors.

Duplo blocks are good. Anything tactile.

you may want to check out https://www.maxiaids.com/toys