Certain health conditions, weather and seasons or nutrient deficiencies can possibly contribute to a weak immune system. Chronic stress, either physiological or emotional can also play a part in the feeling of unwell and could make you susceptible to health issues. Feeling fatigued or lethargic can be signs of possible underlying imbalances.
Fatigue and lethargy can be accompanied by the immune system allowing illness and delaying recovery. A less than optimal immune system, together with eye sensitivity, could be a signal that your Vitamin A levels are not adequate. HealthAid