Refractive Errors

Refractive errors reduce your visual acuity, but can be corrected through glasses, contacts or refractive surgery.

In normal vision, light enters the eye and passes through the cornea and lens. These two structures work together to bend (refract) and focus these light rays precisely onto the retina – the sensitive nerve tissue on the back of the eye that converts light images into electrical impulses and sends them through the optic nerve to the brain. With any of the common refractive errors, light rays do not focus precisely on the retina, resulting in poor vision due to reduced visual acuity. Henry Ford ophthalmologists treat and correct all refractive conditions.

Refractive error: Nearsightedness (myopia)

This is the most common of the refractive conditions, affecting almost one-third of all Americans. In nearsightedness:

• The eye is too long or the cornea is too steeply shaped.
• Light rays refract to a focal point in front of the retina instead of focusing precisely on the retina.
• Distant objects appear out of focus and close objects appear clearer.

Refractive error: Farsightedness (hyperopia)

This refractive condition occurs when the eye is too short or the cornea is too flat. In farsightedness:

• Light rays are refracted to a focal point behind the retina, causing distant objects to appear clearer while close objects appear relatively more out of focus.
• The effects can vary with age.

Refractive error: Astigmatism

Affecting both near and distant vision, this refractive condition occurs when the cornea has multiple curvatures. A normal cornea is round in shape, like a basketball, while an astigmatic cornea is shaped like a football. In astigmatism:

• Light scatters to many different focal points and it cannot be clearly focused.
• Large amounts are inherited and remain mostly unchanged throughout one’s life.
• Small amounts – which can be acquired at any time – are common and should not require correction.

Refractive error: Presbyopia

The need for reading glasses as you get older is caused by presbyopia, a refractive condition where the lens of the eye loses flexibility, making it difficult to read. This typically begins to occur between the ages of 40 and 50.

Treatment for refractive conditions

All common refractive errors may be treated with eyeglasses and contact lenses. Refractive surgery – including LASIK, PRK and specialized intraocular lens implants – also may correct these eye conditions.

Monovision for presbyopia

This treatment is used as an alternative to bifocals in some patients, and works by using different contact lenses, intraocular lenses or laser surgical corrections to correct near vision in one eye, and to correct far vision in the other eye. These two corrective forces, when used together in standard binocular vision, typically balance out to correct the refractive error and make a person’s vision appear normal.

Eye refractive surgery experts

Henry Ford Ophthalmology is a leader in refractive surgery, using the latest in refractive technology to correct refractive errors. Our expert surgeons will complete a thorough evaluation of your eyes and recommend the procedure we feel is safest and best for your eyes.

At Henry Ford, patients come first.

The Henry Ford Department of Ophthalmology is committed to providing our patients with compassionate, personalized care. We feature the most advanced treatments in eye care and are dedicated to vision research – always staying at the forefront of innovation. A leader in Michigan, as well as one of the largest ophthalmology practices in the United States, we treat more than 55,000 patients per year at several locations throughout southeast Michigan. In addition, our team works closely with Henry Ford Medical Group physicians in other departments, providing multidisciplinary, coordinated care for those patients who need it.