In our paper, we will describe our research in the field of developing programming environments for lower secondary blind students. We will present two text-based programming environments developed by our students of applied informatics.

The first one is called Musik and focuses on programming simple melodies. Basic commands allow to play a note or chord of a specified length and volume. There is also a command to set up a musical instrument to play a sequence of notes and chords. It is possible to choose from ten musical instruments, while four instruments can play simultaneously at the same time. In addition, students can use more advanced programming concepts such as loop, branching, threads, subroutine, variable. The environment contributes to the development of children's creativity and algorithmic thinking without having to imagine what is happening on the screen.

However, it is important for the profession of programmer to be familiar with the computer screen. Therefore, the second programming environment Coshi 2 enabling to control a virtual robot in a square grid with assigned sounds. It is possible to change an audio layout and thus create a new microworld with different motivation. The programming language used in Coshi 2 is easy with basic absolute direction motion commands – Up, Down, Right, Left. These commands move the robot in a chosen direction. In Coshi 2, there are also structure commands – namely a counting cycle (FOR cycle), a conditional cycle (WHILE cycle), conditional branching (IF-THEN-ELSE), a procedure without parameter, and a number variable.

Both environments were validated in several iterations with different types of users - teacher of blind students, blind programmer, blind student. For each environment, we created a set of graded tasks for users to perform. The teacher of the blind and the blind programmer provided us with their insights and comments in written form. During the verification by the blind student, we conducted participating observations and took notes.

We have focused on the following aspects:
- Accessibility of environments for the blind.
- User-friendliness and intuitiveness.
- Clarity of programming language commands.
- Attractiveness and age appropriateness.

In the paper, we present the results of the verification. Based on our findings, we will present the features of a programming environment suitable for lower-secondary blind students and outline our plans for further validation of the developed environments.

Keywords: Blind students, accessibility, learning programming.