blind eye, one eye
瞎 centers on a damaged or non-functional eye: a blind eye, or having only one working eye.
瞎 combines 目 (eye) with 害, which likely contributes the sound and the idea of damage or harm, suggesting an eye that is damaged or blind.
The eye 目 is harmed 害, leaving it blind or with only one functional eye.
For カツ, imagine a blind eye covered by a thick cut (カツ) of meat: the cut blocks vision, and カツ sounds like 'cut'.