when there are students with VI in the classrooms, as teachers we need to focus on auditory mode of teaching, visuals should be verbalised, demonstrations should be modified as hands on activity with clear directions, say for example if you are showing different kinds of leaves--allow children with VI to touch and identify the difference in the leaves using touch, smell, shape etc. Involve sighted students also in identifying the difference through non-visual modes. 

As far assessment is concerned, appropriate need based modifications and provisions exists for year end examinations and CBSE and other state boards respect individual needs and make allowances for special needs.