Q: What exactly is astigmatism?
A: Usually it is related to the shape factor of the front surface of the eye called the cornea. Instead of being shaped spherically like a ball bearing or a marble, it is shaped like a football, being more curved in one direction than the other. This brings light to focus at more than 1 point. The root word stigma means point and the prefix A means without a point focus in the eye.
Q: Does reading my smart phone or tablet in the dark damage my eyes?
A: Reading from a tablet or smart phone in the dark is okay for your eyes, as long as this is not for a long period of time. There is good lighting from these devices, with good contrast. There is, however, blue light emitted from these devices. Blue light is a short wavelength light, with high energy that may cause damage to the structures of the eye if exposed for a long period of time. As well, studies have shown this blue light can disrupt melatonin production which is required for a healthy sleep cycle. Doctors of Optometry recommend limiting screen use during the last hour before bedtime.
Q: What are cataracts and how do they affect my vision?
A: A cataract is a gradual clouding of the crystalline lens, located inside the eye, causing decreased vision. Cataracts most commonly occur with aging, and are a normal part of the aging process. Other causes of cataract development include ocular trauma/surgery, radiation, smoking, systemic disease (metabolic and genetic conditions), and certain medications (particularly corticosteroids). Symptoms of cataract vision loss depend on the type, location, and severity of the cataract. Cataracts may cause gradual blurry vision, halos around lights, poor night vision, prescription changes, and glare symptoms. A cataract is treated with outpatient surgery, in which the crystalline lens is removed and replaced with a clear lens implant. Surgery is typically done with local anesthesia, with minimal or no complications. Nearly all patients achieve improved vision and often do not require glasses post surgery. Cataract surgery is one of the safest and most common surgeries performed in the United States. Your optometrist will evaluate your eyes for cataracts at each comprehensive eye exam. Please let your optometrist know if you experience any of the above symptoms.