An eye that can normally bend light onto the retina is an emmetropic eye. However, different aberrations in the shape of the eye can lead to refractive errors. The most common form is myopia, or near-sightedness. 

There are other types of refractive errors too.

• Hyperopia
  Also known as hypermetropia and far- or long-sightedness, this is a condition where the focal point of light from near objects lands ‘behind’ the retina instead of on it. Young people with hyperopia struggle to see near objects. Adults with the condition may struggle to see both near and distant objects clearly. This occurs when the eyeball is too ‘short’, or the eye’s refractive power is too weak to resolve on to the retina. 
• Astigmatism
  The aberration here is generated by a misshapen or uneven cornea and/or lens, which generates two or more focal points on the retina. In people with astigmatism, both near and distant objects appear blurry or distorted. In many people, astigmatism appears along with myopia and hypermetropia.
  
  Spectacles are best suited to correct the aberrations caused by this condition.
• Presbyopia
  A common condition among those who are 40 years and older, presbyopia is when a person struggles to resolve near objects, like text on a medicine strip, with clarity. Presbyopia is part of the ageing process, where the crystalline lens and the intraocular muscles that operate it lose their suppleness and elasticity.
• Anisometropia
  This is a condition where the refractive error between the two eyes of a person is significantly different. Our brain fuses image information from the two eyes into one. In people with anisometropia with glasses for correction, the brain receives two differently sized images, and the brain struggles to fuse them into one. Ultimately, it may choose to supress one eye over the other.

Different refractive errors may have different symptoms, including:

• Hazy or blurry vision

• Glare or haloes around lamps and lights
• Squinting at distant (like a blackboard) or near objects (like a newspaper)
• Headache or strain
• Impaired depth perception

Correcting refractive errors require a balance between subjective assessment and objective measurement of power. Optometrists at LVPEI are trained to be amongst the best in the country to help you find a good fit for your needs.

Correcting refractive errors in most people requires a simple pair of glasses. Here are some options:

• Spectacles: Eyeglasses, an 800-year-old invention, are one of the best means for correcting refractive errors. Spectacles can hold a range of lens: from single power, to bifocal, to more complex lenses like progressive lenses or defocus lenses.
• Contact lens: Contact lenses are made of silicone hydrogel or other such oxygen permeable material and sit on the black part of our eyes. There are different kinds of contact lenses including special, large diameter scleral lenses for those with special needs. Research at LVPEI has played a key role in developing some of these lenses.
• Refractive surgery: IThere are many new high-quality surgeries to correct aberrations of the eye. These include laser eye surgery or LASIK, photorefractive keratectomy (PRK), small incision lenticule extraction (SMILE), laser subepithelial keratomileusis (LASEK) and more.

Speak to your eye doctor and find out what is best suited for your needs.