I purchased this product for my dad who has been diagnosed with retinitis pigmentosa (RP). He has very limited vision but noticed that his night vision had gotten gradually worse so I did some research and came across this product. It seemed like a really good product that provided a natural alternative to offer some relief for my dad's failing eyesight. He took the recommended dosage daily for the last month and did not notice any improvement in his night vision. I'm not sure if his condition hampered the effectiveness of this product but for what it states, I have to rate it a failure.