If you've been looking for an excuse to indulge, research shows that eating chocolate could improve your vision. Reading University boffins asked participants to read coloured numbers that faded progressively until they disappeared. Eating 35g of dark chocolate improved their performance improved by 17% percent. The effects, which were was almost instant and lasted for more than two-and-a- half hours, were attributed to flavonols - antioxidants found in cocoa.