European Journal of Ophthalmology evaluated people taking a combination of nutrients (Lutein, Zeaxanthin, Astaxanthin, Vitamin C, Vitamin E, Zinc, Copper) for 24 months. Results showed that 39.5% of those taking the nutrient combination saw an improvement in their contrast sensitivity, while 49.3% maintained their contrast sensitivity. Conversely, the untreated group saw a 40.9% decline in their contrast sensitivity.
Archives of Otolaryngology-Head Neck Surgery found NAC to be a powerful mucus-buster. After treating thick, sticky mucus with NAC, the mucus began to dissolve in just 30 minutes. After one hour, mucus was flowing easily. Even better, the results lasted for four hours. When compared to untreated mucus, NAC improved slipperiness by up to 45 percent for better flow. And, NAC reduced stickiness by up to 30 percent.