Introduction

‘Tunnel Vision’ is a vision defect where objects cannot be seen unless they are near the centre of the visual field.¹

There are two types of cells in the retina that respond to light: rods and cones. The cones are present in the centre of the retina and are responsible for colour vision. The rest of the retina is covered with rods, which are responsible for peripheral and night vision.¹

Tunnel vision is the inhibition of the function of the rods, resulting in peripheral vision loss while the cones continue to function.¹

Tunnel vision can also be accompanied by night vision problems.¹

Causes

There are different causes of tunnel vision. Some are more serious compared to others.

Damage to the optic nerve

The function of the optic nerve is to transmit signals from the eyes to the brain. Any damage occurring to the optic nerve, either through trauma or disease, can cause tunnel vision to occur. Glaucoma is a common eye disease in which the optic nerve is damaged as the pressure inside the eye is increased. Glaucoma leads to a slow but steady loss of peripheral vision.²

Damage to the retina

Peripheral vision is affected by the impairment of the peripheral areas of the retina. A condition called ‘retinitis pigmentosa’ is reported to cause tunnel vision by damaging the retina, but it is quite rare.²

Damage to the brain

A stroke or reduced blood flow to the brain can lead to peripheral loss of vision.²

Temporary tunnel vision

When the body produces high levels of adrenaline, it leads to temporary tunnel vision. Extreme stress, panic, or anger can affect peripheral vision. Alcohol and drugs also cause loss of peripheral vision. In such cases, normal vision usually returns on its own.²

Migraine

Migraines can cause visual disturbances, including tunnel vision. Migraines can be the result of various ocular and nervous stimuli and can last from 10 minutes to many hours.³

Symptoms

The symptoms usually show gradual advancement and are unnoticed at first.

• Blurred edge of vision.
• Compromised balance.
• Headaches.
• Eye fatigue.

In extreme cases, there can be a complete loss of peripheral vision in patients with tunnel vision, which results in difficulty with maintaining balance. It is crucial to consult an eye doctor if any of these symptoms are experienced.³

Lifestyle modifications

Nutrition

A healthy, balanced diet rich in fruit and vegetables is beneficial to the retina as well as for overall well-being. It is advised to eat green leafy vegetables such as kale, spinach, and broccoli, and fruits such as berries. Including two portions of fish each week is also recommended.⁴

Avoid smoking

It is reported that smoking tobacco is harmful to the retina. Thus, it is recommended that those people with inherited sight loss should avoid smoking and also avoid environments in which they could be exposed to cigarette smoke. Evidence also suggests that even passive smoking can further deteriorate the pre-existing visual impairment and can also increase the risk of developing cataracts.⁴

Adapting to vision loss

Magnifiers

Physical or electronic magnifiers can be used if you are not comfortable getting reading glasses. These tools are easier to use and can adjust the level of magnification as required if electric models are used. These help with reading and seeing things clearly.⁵

Better lighting

If your rooms are lit up properly or if special high contrast lights are used, it can help to see better with fleeting vision. Combined with the other solutions, this can help you make yours easily visible without having to make significant changes.⁵

Vision therapy and training 

This is one of the most vital solutions for adapting to vision loss. With vision therapy and training, your brain can be trained to go through life normally without being dependent on others. It involves other solutions alongside vision therapy that can reduce the speed at which your vision degrades.⁵

Audiobooks

Audiobooks and/or any audio-based entertainment options can provide relief. New inclusive technologies like audiobooks, text-to-speech, and screen readers help patients interact with entertainment and digital devices around them. These technologies enable them to stay updated and not miss out on anything.⁵

Canes

White canes are helpful to visually impaired people for interaction with their surroundings and to avoid stumbling. But these are only required if the central vision of the person gets affected and should not be used unless they are legally or totally blind.⁵

GPS devices

GPS devices can enable the user to become aware of the upcoming obstructions or traffic. These help the patients in navigating the outside world. However, these can be best used where the network connectivity is optimum and are not recommended where there are connectivity issues.⁵

Decluttering and organising the home

Make space in the house and create more walking space. Get tools that help in arranging things very neatly in compartments. Get organisers as it will create a habit of storing things in the same place every time, and will be helpful in making you independent. Remove furniture if a lot of it is present, as this will avoid the risk of falling or bumping into objects.⁵

Acceptance

The first step is coping and coming to terms with this disease. It is important to emotionally accept the condition. This will enable you to take proactive steps to help deal with the condition.⁵

Get the help you need

It is ok to ask for help and talk with your loved ones and people whom you can trust. Take it slow. It is also advisable to seek support from support groups and counselling. Build a network of supportive friends and family to sail through life.⁵

Proactive measures 

It is important to take the necessary steps to support yourself. The doctors will guide you through treatment options and help manage the condition.⁵

Developing hobbies and interests

Hobbies and interests help you get through life and give you a sense of normality. Indoor games, crafting, gardening, and exercising can be done to adapt to the new lifestyle.⁵

Summary

When there is a loss of peripheral vision, the person is likely to have developed tunnel vision. Rods and cones are two types of cells present in the retina that respond to light. Usually, tunnel vision is the result of impairment of the rods. There are many different causes of tunnel vision, such as damage to the optic nerve, damage to the retina, damage to the brain, temporary tunnel vision, and migraine. The symptoms are gradual and go unnoticed at first. A healthy, balanced diet is recommended for the retina, and it is advisable to avoid smoking as well. This article mentioned various other parameters which enable the person to deal with the condition and adapt to their daily routine accordingly.