Modifided Subtitle 4 the Deaf with Vision Impaired

I've known the deaf people having trouble reading with vision impaired so I have to signs for them, impaired mean colour blinds, can't read white fonts without heavy shadow, some with tunnel vision that they only see centre with dark surrounding, increasing, shrinking or move the fonts to a person's preferences like if the subtitles covered the faces so you cannot lip-reads or read expressions as well so for social life we would handy to have to do the practising from the CD/DVD/Blu-Ray. Thanks you for reading this from me and millions of others.