Taking Fildena 100mg for erectile dysfunction can cause side effects. Some of these side effects are more serious than others and may not go away without medical treatment. You should always tell your doctor if you experience any of these side effects. A sudden loss of vision is one of the more common side effects of sildenafil. People with crowded optic discs or retinitis pigmentosa may be at a higher risk of developing vision problems. Symptoms of vision loss include blurred vision and increased sensitivity to light. The cause of this problem is not yet known. If you experience any type of sudden loss of vision, stop taking sildenafil immediately. You should also check with your doctor if you experience hearing loss.