Upon being diagnosed with age-related macular degeneration, it is perfectly normal for some people to go through a period of mild depression as they begin to grieve their loss and adjust their lives. One study showed that AMD sufferers are nearly three times more at risk of depression than the general population.
Consider this list of symptoms that could call for treatment:
Withdrawing socially
Fatigue or loss of energy
Insomnia
Weight gain/loss
For more info:
http://www.amdblog.org/macular-degeneration/preventing-depression-in-macular-degeneration-patients/