Most people with glaucoma are not aware they have it as they experience no obvious symptoms. Stats tell us that due to the silent progression of the disease (at least in its early stages), up to 50% of people with glaucoma in developed countries are not even aware of having glaucoma. This number in underdeveloped countries may rise to 90%. Seeing halos around lights is sometimes the first sign of glaucoma. As the disease progresses, peripheral or side vision is lost. This loss may cause the affected person to bump into things or miss things in their periphery.