The above posters are on the right path. Please see an opthalmologist as soon as possible, your sight is too precious to play with.
hey buddy i dont want to alarm you butMuncher1, is on point you need immediate attention and if i had to guess id say a small stroke or an internal violent trauma is taking place or already has ,,, good luck god blesss
Not a lot of information to go on but loss of vision is a red flag symptom and requires urgent investigation. Is this the first time this has happened? how long does it last and do you have any other neurological symptoms. Does your vision go completely or is it just reduced.
My initial thought is MS, which is a condition of demyelination most common in women 30 years of age although men also suffer from it.
How short term? Hours, days or weeks?