Instruct: Classify Amazon reviews into positive or negative sentiment
Query: I could not take these.

I wanted to try green tea extract for the remote but possible chance for weight loss benefits alongside my diet and exercise plan. A couple of days in I started to have wavy distortions in my vision that made working difficulty. Because I also have floaters and glasses, I was concerned that I may have developed a problem with my retinas. I ran to my optometrist immediately and their diagnosis was that caffeine in the extract was causing migraines that were manifesting visually, without pain. I've had migraines in years past, and I didn't know that they could be like this. I immediately discontinued use, and the problem went away. Obviously this is non-scientific, so I am not urging you to avoid this product. I am suggesting that you draw your own conclusions before buying. Several others seemed pleased with this product, so this could be a product of my own unique physiology.