Mossberg 500, Remington 870, Maverick 88 are reliable, basic pump guns that are well suited for home defense purposes.
Not knowing the degree of your visual impairment I have to agree with the other posts and ask, is a gun really a good choice? Not being glib or judgemental here but if there is a chance that you could accidently shoot and kill a neighbor, family member or any other innocent party because you could not identify them due to your impairment then the answer is a firm no. Perhaps a loud dog is a safer alternative.
"The whole of the Bill (of Rights) is a declaration of the right of the people at large or considered as individuals.... It establishes some rights of the individual as unalienable and which consequently, no majority has a right to deprive them of." (Albert Gallatin of the New York Historical Society, October 7, 1789)
"A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." - George Washington