Farsightedness (hyperopia) is when a person can see distant objects clearly but have difficulty focusing on near objects. People with severe hyperopia can only focus on objects far away, or they cannot focus at all.
People with farsightedness can see objects farther away better than closer objects. It occurs when the eyeball or the lens is too short or the cornea is too flat.
Also known as longsightedness or hyperopia, it affects
It can either develop as the muscles weaken from approximately 40 years of age onwards, also known as presbyopia, or be present from birth.
The most common signs and symptoms of farsightedness:
- objects nearby appear blurry
- the person needs to squint or strain their eyes to see clearly
- a headache or discomfort occurs after prolonged reading or writing
- eyestrain develops, which burns or aches in or around the eyes
- the person cannot perceive depth effectively
Untreated, other eye conditions can develop, such as a “lazy” eye or crossed eyes, known as strabismus.
Two parts of the human eye make it possible to focus.
The cornea: The clear, front part of the eye that receives and focuses light into the eye.
The lens: A transparent structure inside the eye that focuses light rays onto the retina.
The retina is a layer of nerves at the back of the eye that senses light and sends impulses through the optic nerve to the brain.
The optic nerve connects the eye to the brain and carries these focused light signals formed by the retina to the brain. The brain then interprets them as images.
The optimal shape for an eye is a perfectly smooth curvature of the cornea and lens. The length and shape of the eyeball also need to be optimal for perfect vision.
The cornea and the lens refract — or bend — the incoming light rays. When this happens, an image is focused sharply on the retina.
Farsightedness occurs when light does not refract properly. Instead, the light refracts through an uneven, less smooth cornea or lens. It is a type of refractive error. Refractive errors can also cause myopia, or shortsightedness, and astigmatism.
The light rays focus at a point behind the retina but not onto it due to the imperfect shape. They travel to the back of the retina before they have been bent properly by the lens and cornea, resulting in blurred vision when objects are closer.
People who are born with hyperopia may be able to focus on distant objects during childhood. However, eventually, it may become more difficult to focus, and even distant objects may not be clear.
In rare cases, farsightedness may result from:
- diabetes
- tumors
- fovea hypoplasia, or macular hypoplasia — a rare medical condition involving the underdevelopment of the macula, a small area on the retina
Experts often link macular hypoplasia with albinism. They also believe farsightedness may be hereditary.
An optometrist can perform a standard eye exam to diagnose farsightedness.
Optometrists can assess vision, prescribe corrective lenses, and diagnose common eye issues. Alternatively, an ophthalmologist, or eye specialist, may carry out the exam if a more complex issue is suspected.
A person should have an eye exam if they are experiencing any of the above symptoms or reach 40 years of age without symptoms of farsightedness.
Younger children should also have vision testing at the following stages:
- at birth
- during their first year of life
- around 3.5 years
- around 5 years
A person who already wears corrective lenses will need more frequent exams to ensure their lens prescription remains appropriate.
Most eye conditions can be corrected successfully, but there is a risk of further complications if left untreated.
A complete eye test should check the following:
- ability to focus on near objects
- general eye health, to determine whether there are any eye conditions or physical abnormalities
- visual acuity, or sharpness, using a Snellen chart of letters that decrease in size dilation, or widening, of pupils
- side vision
- ocular motility, or eye movement
- the front of the eye
- retina and optic nerve
If a person wears prescription eyeglasses or contact lenses, they may need to wear them during the exam.
The eye specialist also checks for signs of eye conditions by shining a light into the person’s eyes and observing their reaction. They will look for disorders such as glaucoma or diabetic retinopathy.
Longsightedness is thought to be hereditary, caused by misshapen eyes. Farsightedness may worsen after the age of 40, but it is easily treatable with corrective lenses or surgery.