There are a number of reasons why your normal lenses may feel uncomfortable. You may be developing a cold, or there may be deposits on the lens, or a nick in one of the edges. There may be some debris on the lens, so start by rinsing the lens with saline or lens comfort solution (never with water or solutions that are not designed for rinsing). You can try your usual deposit-removing routine if you use one. If these cleaning steps do not solve the problem, you should never continue to wear the lens and try to ignore the irritation - this could damage the surface of your eye. Consult your optician instead.