Well, I can see you are a little bit concerned about your eyes, for their color change from time to time. Anyway, you should know the color of our eyes would somehow change according to some factors, such as panic, emergent situations, traumas, or climate and geographic locations. For example, people near the tropical areas would have different eyes from those near the polar. And if you detect any strange problems, you should perhaps go to see a doctor.
Yes, it's normal for our eyes to get lighter in summer, owing to the weather can change your eyes color in some ways. The weather in summer is very hot, and when it is really sunny outside, it can cause your eye color to become brighter. Thus your eyes will seems lighter in this condition. By the way, the emotion is also a reason to make your eyes seems different. For example, if your emotion is low, the eye color can turn to light grey and light blue. Hope these tips above can be helped.
It is not normal. You may feel it from the psyche. Your eyes may get dry. That is the main reason for your lighter eyes. You need to pay attention to it. You could eat more food with vitamin C which will moisture your eyes. In addition, you could also use the eyes drops to moisture the eyes.