I can't see black things

I am 74  shortsighted and have strange occurancies with my eyes mainly which are temporary but one seems to be permanent is i can't see black things.  I can drop my black remote on my pale fawn carpet and totally miss seeing it there.  
Going out causes problems as all the insides of my bags and purses are black and i can't see a thing at checkouts etc I am fumbling around ages and can only go by touch at these times.
It was awful recently when my son decided to dropin with with his family. My gate was locked and they was all wearing black along the railings calling me - and with sunglasses on.too.  I called out twice 'who are you?. 'This is your son Mum'
All I could see was 5 little white circles around their black lenses- nothing else

Do you know of this problem?
Thankyou

[John C Hagan III, MD, FACS, FAAO]

It could be due to a number of things including cataracts and macular disease. I suggest you see an Eye MD ophthalmologist in the very near future.

JCH MD