Refractive errors and binocular vision disorders
Myopia is a very common refractive error. it means that the eye is either too powerful or too long resulting in blurry vision from far but good vision from near. This can be corrected by glasses, contact lenses or LASIK surgery
Hyperopia is almost the opposite problem: the eye is too short or not powerful enough. It can lead to different symptoms depending on the age of the patient: Young hyperope: the eye is able to adjust its power by a mechanism called accommodation. Most young hyperope are able to see fine from far and near but some of them will have symptoms due to the effort. Symptoms of hyperopia can be eye discomfort, headaches, difficulties focusing Older hyperope: with age, our accommodation ability decreases. At some point those patients start experiencing blur upclose and later blur from far as well. An hyperope with no accommodation left will see blurry from far and near. This is different from presbyopia
Astigmatism means the eye actually has 2 powers depending on the direction. For instance a patient can have myopia in a vertical direction and hyperopia in the horizontal plane. Astigmatism is extremely common and goes along with hyperopia or myopia. Its compensated for by toric lenses, on glasses or contact lenses, or surgery.
Presbyopia affects every adult after the age of 42-43. It means, that despite the perfect distance glasses prescription, the eye is unable to focus on objects upclose. It is due to the fact that with age our ability to accommodate (use our internal eye muscles) to focus upclose, diminishes...to a point where there is none. Early on, young presbyopes patients tend to read further away or use more light. Shortly after they need glasses to help them read upclose, then to read in the intermediate range (computers). This is compensated by bifocals or progressive lenses.
Strabismus (Eye Turn)
Strabismus (Eye Turn) means that one of the eyes is permanently not aligned. When both eyes are opened, one eye is looking at the target, ant eh other eye shows a deviation. The deviated eye can be inward (ESOtropia), outward (EXOtropia) or up/down (HyperTropia). When tis deviation is not permanent but happens sometimes, when the patient is tired for instance, it's called a phoria
Phoria is the intermittent deviation of one eye, at times. Usually the strong eye maintains the fixation while the "weak" one deviates. The eye can deviates inwards (ESOphoria), outwards (EXOphoria), or up/down (Hyperphoria). In other words, when the eyes are in rest position , they are not straight aligned. That means in "active" "awake" position, the eye muscles have to align the eyes on the target. This effort can lead to symptoms for the patient. If it is a problem, your eye doctor can use prisms or visual training to correct or alleviate the problem. Visual training is basically an eye muscle work out.
When a Strabismus or eye turn develops in a child, this can lead to amblyopia or lazy eye
Amblyopia (Lazy eye):
Amblyopia (Lazy eye) means that the visual acuity of one of the eye is weak because of lack of stimulation. During child development , when one eye does receive a clear image, the brain tries to eliminate, or not take into account that image. That means that the brain and the eye never develop correctly. During childhood your optometrist can fix that problem, usually by prescription the proper glasses prescription and sometimes patch the good eye, to force the weak eye to work. If this is not addressed during childhood, the weak eye will never have 20/20 vision. It is very important all kids are seen regularly to make sure there is no strabismus or amblyopia so the problem can be fixed. Your eye doctor in North Miami is happy to examine your child after the age of 3.